Archive for the ‘Snakes’ Category

!! RATTLERS #4!!

June 8, 2007

        Well here I am again attempting to wrap up this series on rattlesnakes.  I just published number three last night, and this morning I discovered a comment on it from my old Marine Corps buddy that lives in Rosemond, Ca.  In his comment he stated that his daughter and husband have just moved to Lancaster and in the last two weeks have killed two Mojave Green Rattlesnakes on their front pourch.  Wow, that is scary the Mojave has a combonition of haemotoxic and neurotoxic venom.  Neurotoxic as I will shortly explain is the most dangerious of the two.  The Mojave is probably the most dangerious and poisionious snake by volume in the country.  Nuff for now, will get in to the meat of the story now.  Just a warning to Karen, watch your toes and legs kid.

    HIBERNATION

      In the winter months the tempatures do rise high enugh to allow the rattler to function.  In order to survive the cold months the animal has adopted the form of hibernating. 

     Hibernation can take several forms, in warmer areas it may be just for short times, days or even weeks at a time interspersed by warmer spells, when they can emerge and function for a time.  these species shelter singly or in small groups.  In colder areas, a more or less continious hibernation occors, sometime for many months.  the Timber rattler in the northern latitudes hibernat for up to seven months out of the year.

     Where the density of the snake population is high and sutiable areas of space ar rare, rattlesnakes congereate in large dens, located in deep crevices or holes and galleries in the earth.  several hundred rattlesnakes may use the same den.  Many of the large dens have been located and destroyed in the past, so the hugh numbers recorded in the past may never be seen again.  the Great Basin rattlesnake andthe northern Pacific rattlesnake are thought to form the largest aggregations, exceptionally up to 1,000 individuals.   Other groups that hibernate together are the western diamonsback, the red diamondback and the speckled rattlesnake.  these are found in smaller numbers of around fifty to a den.  In the east  the only species that seem to group together is the timber rattler  with 200 seeming to be the max.

      Often  after emergimg from hibernation they are found basking in the sun for a few days.  this is called “lying out”.  Traditionaly the large rattlesnake hunts or “roundups” are held during this lying out period to ensure the maximum number of snakes slaughtered.  (mans way of destroying nature in the name of fun, my editorial for the day).

HOME RANGES

     Most rattlesnakes appear to have home ranges – areas in which they can predictably be found.  Home ranges may well be far from where they hibernate (logically, two hundred snakes could not share the same hunting area).  Some snakes may travel great distances from their dens to a home range.  Having a home range proboably helps themt feed more efficently because they know the patch of ground they live on and can predict where food can be found.

FEEDING

      After tempature regulation, feeding is the next important rattlssnake activity.  their feeding habits have to a large extent beeen  the driving force behind their evolution of their venom apparatus and the rattle.

         Since the most specilised sense organs, the heat pits evolved to detect the presence of warm objects, it is hardly supprising that warm-bloodes prey is the most likely food source.  the most important prey therefore is small mammals.  No species do not eat mammals and many nothing else.  It is unlikely that they have any paticular prefernce as long as it will fit in to their mouth.  Taken overall it is estemated that 85 percent of their diet is small mammals.  Of course their most common prey will be what is ever prevalant in their area.  This will include mice, kangaroo and wood rats , and slightly larger for the larger snake, ground squirrels, prairie dogs and  cotton tail rabbits.  Only some of the larger snakes can swallow the adults of some of the fore going.

     Birds form the second largest group of their diets.  These would be the ground nesting birds and their eggs and chicks.  Although some rattlers have been known to crawl into low brush and srubs after roosting birds.

     The remaning five percent of the diet consists of amphibians, lizzards and other snakes.  It must be noted that all of these are indeed cold-blooded also and are not a really viable source of heat for the heat- pits to home in on.  A basking lizzard my give of a slightly warmer target than the surrounding area but most likely these meals are just targets of chance.

METHODS OF HUNTING

          Like I have alread stated next to tempature control, hunting and feeding is the  largest porportion of a snakes waking hours.  Not only because they eat large numbers of prey, but because hunting and stalking is time consuming.  Rattlesnakes are sit and wait hunters.  Many nights and hours are unproductive a snakes sucess relies on its patience.  So  lets take a hypothetical snake and follow it on a nights hunt.

           Activity begins as the sun goes down and the ground begins to cool, this is when the rodents become active.  Our rattler rouses itself and makes for a place where it is likely a fat chunk of meat may make a aperance.  Once in position the snake  puts several bends in its neck ready to strike and settels to wait.  After several hours nothing has apeared and the ground begns to cool and the hunt must be abandoned for the night and it retreats for the night ot a place of saftey and some warmth, appetite unsatisfied.  This may happen for several nights, sometimes even weeks before prey materilizes.  Evolution will have told the snake when to seek a new area for food.

     When prey does appear the rattlers formatable array of sense organs jump into play.  It may be alerted to the presence by vibrations caused by the activity of its quarry.  It starts by flicking its tongue, picking up the sent molecues in the air and transfering them to the Jacobsons organ in its mouth.  detecting the source of the vibrations, maybe a mouse, it uses its heat pits to locate its position.  Even if the mouse senses the snakes presence and freezes its body will still give of the heat neded to pinpoint its exact position.  If the mouse is out of range the snake will either wait for it to move closer or will edge closer in the rectiliner motion mentioned earlier.  It may stalk the mouse like this untill with in range.  Then with lightning speed the rattler strikes, with mouth opened wide driving its fangs deep into the chest area.  Closing its jaws it then pumps the venom in to the victum.  The snake them recoils maybe opening and closeing its jaws several times to realign its jaws.  Meanwhile the mouse will stagger around getting weaker until it colapses. 

     a

     After a few minutes the snake begins to flick its tounge over the ground where the mouse was to locate it.  Now it searches for the head and begins to swallow it by drawing it in with its fangs one side at a time until it reaches the snakes throat where muscel contractions finishes the swallowing process.  By this time the digestion process is well under way due to the enzymes in the venom.

     Rattlesnakes will eat road kill more so than other snakes, as they are programed to eat already dead kills due to their venom. ( I belive I mentioed the series of photos of a rattler swallowing a large fish it found on a river bank).  They have been reported of eating animals dead several hours or days.

“finally”

VENOM: COMPOSITION AND EFFECTS

      Rattlesnake venom consists largely of proteins,  mainly in the form of enzymes.  There are at least 10 diffent enzymes in all snake venom and as many as 20 in some.  Enzymes cause biocemical reactions inside and outside animal cells,  effectively breaking them down.  In effect,  snake venom is a very strong solution of digestive juices that can be injected into a animal by biting (as a note the sting of a scorpion is much the same).   Snake venom varies from species to species by composition, its effect also differs. 

     The strength of  a snakes venom depends on several factors.     While the  venom of some is more potent than others, the volum of a bite must be considered, this is called the “yeild”

     Venmous snakes produce a cocktail of venom contaning more than one vareity, althouth one type usually is more predominate.  Snake bites vary according to which type of venom is more predominate.

     Most viper venom acts mainly on the blood and citculatory system of their prey.   This is known as “haemotoxic” venom.  the other works on the nervious seystem and is known as ” neurotoxic”   although it is dangerious to generalise,  Neurotoxins tend to act quicker than haemotoxins.  They also produce little pain at the site of the bite,  but cause breathing problems and pralysis.  Hametoxins cause imedate pain at the site of the bite , massive brusing and internal haemorrhaging, followed by permante tissue damage.

     Now I am going to vear away from the books I have been quoting and go to a report I found online on the National History Magazine web site.  the article was from 2000.  The article stated that previously people bitten by rattlesnakes which had a predominatly solution of haemotoxin venom were almost always expected to live,  Especillay after the 1930’s with the event of antivenom ( produced by injecting horses with a small dose of venom and allowing them to produce a natural resistance to it).  It stated that a person has at least a two hour window to get treatment?  Neurotoxins however dosn’t allow such leasure because it blocks  nerve impulses to muscles including the diaphragm used for breathing,  (the article recounts several difftent cases if you wish to prusue them).  Neurotoxin bites can cause immediate shortness of breath, weakness or paralysis of lower limbs, double vision ect. and death can occour in as little as ten minutes, usually due to disruption of breathing.

     Now for the part I find destressing.  Of the fiveteen species of rattlesnake found n the United States at least ten have been verified as having neurotoxins in their venom.  Untill recently (2000) however the low levels of these chemicals in the overall mix were not considered much of a threat to humans.  In this report there are indications that more neurotoxins  in greater consertraton are showing up in some of the other ratlesnakes  than in the past.  The question is, are the  Mojave rattlers inter -breeding with the adjecent rattler populations increaseing their potinecy?  Or are  the other snakes developing a stronger mixture for changing hunting pratices?  I guess the debate in the scientific population is in the air.  It just looks like a bad deal is just getting worse.

     Now, I found this info on google under rattlesnake bites.  I invite you to explore further on your own if interested.  Also when there, look for a site  “Justins snake bite”  it recounts the experence of a thirteen year old, on a group hike in Yosmite and the resulting pacific rattlesnake bite to his hand.  he tells of his ordeal and the $700,000 worth of treatment that resulted.  he has a propority claimer on his site so I will not quote his story, but look it up, it is interesting.

      I am not going into the rattlers defense  tatics, as they are self evedent.  As for repoduction lets just say it take two to do it.  Some females remain in the vicnity until the first shed at about six weeks and others abandon them at birth.  They are born ready to function fangs and venom and all.  they do not get a rattle untill sheddng as told in the first installment of this book, length blog.

    I hope you have enjoyed and gained some insite into this amazing creature. and you will give it the respect it needs and deserves.  As I said long ago, he does not set out looking for you and will avoid you if you let him.  When on his turf be respetful, live and let live.

     Well like Porky Pig always says  “Th Th Th That’s all folks”

ramblingbob

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!!RATTLERS #3 !!

June 7, 2007

      I had planned for this be my final chapter on rattlesnakes.  I thought it would cover about all I have discovered and care to know about them.   However by the time I finished with the section on activity patterns, once again the chapter had become pondrus and unweildy (plus I was getting tired and eye strain setting in) I have so much more to finish up with that it will be necessary to do one more chapter.

     In the last chapter I covered the fangs and venom delivery system.  I also stated how they often have a spare set of fangs in their mouths.  During the Memorial Day weekend I watcehd (out of bordom) the second of the Arnold, Terminator movies.  After Arnie and the boy had sprung the Mom from the nut house, there is a scene where they are coming down the desert road to the place where she has a statch of weapons.  As the car is approaching the camera pans down a wire fence along the road.  Mounted on the fence is a series of rattlesnake heads with their mouths streched open.  The head nearest the camera exibets a pair of fangs on the left side of the head nearest the camera.  I had noticed this in the past but had forgotten it until this last time.  Now I’m not suggesting you watch the movie again, but it you ever do, be watchfull for this scene.  Now on to the final chapter.

     Once again I will be leaning heavly on the books I have used in the past and information I have gleaned from the internet.

     As stated in the last chapter rattlesnakes can be found from sothern Canada all the way thru Argentina.  In some places there is only one species and others several my exist side by side.  they are found in every main land state except for Alaska, delaware and Maine (see chapter two for a break down of numbers).

 HABITATS

     Rattlssnakes occupy a number of distinct types of habitats, but avoid several others that are unappealing to them.  There are no aboreal, aquatic or borrowing rattlesnakes.  while it is possiable to find a lone rattler in water, up a tree on in a scrub, this is a exception, often more by accident than by design.  rattlesnakes do not borrow in the trur sense of the word, sidewinders do shuffel down into the sand, but do not burrow.  Other rattlers do spend a great deal of time under ground but use natural crevices and other animals burrows they have taken over.  Rattlers avoid certian habutiates  in that they evolved in in dry, terrestial enviroments and have became to specialised to try out others.  For instance, their rattles which is a asset to them in the prefered habitate would become a libality if they tried to swim, climb or burrow.  Also their facial pits would not function in water and below ground. 

     Moist areas are not very attractive to rattlesnakes.  Only the Massassauga is associated with this kind of habatiat and then only only the population towards the north-east portion of its range.  Here it occours in the damp prairies, meadows and bogs part of the year, and then it migrates to the higher , drier woods and fields for the summer.

     Many species live in the deserts and arid, scrub covered, simi desert regions.  these include the sidewinder which occours only where there is loose sand and sparce vegitation.  The Western Diamondbac , Mojavie and Western rattlesnake all thrive in all sorts of desert habitates.  Mountane species are numerious, especially in Mexico with a few spilling over into the United States.  Living in high rocky places, especiallt south-facing, boulder strewn slopes and talus slide ways.  Other highland species favor grassy meadows and clearing in foret of pine and oak.  In short they can be found all over.

 

ALTITUDE

     The Mexican dusky rattlesnake lives at evevations of up to 15,ooo feet in centeral Mexico, the highest of any American snake. (as a matter of interest  the highest altitude of any snake in the world is the Old World pit viper, there fore related to the rattlesnake , is Agkistrodon himalayanus,  at the altitude of 16,000 feet).  In our nothern latudides the climate is too cold in the winters for the rattler to survive.  In the United Stated the highest altitude attained by the rattlesnake is around 10,800-11,500 by the Western Daimondback in the Serria Nevada mountains ranges of sothern California.      This rattler has a especially wide range as it is also found below sea level in the Salton Sea area of California.  The sidewinder is found below sea level in Death Valley.

LOCOMOTION

     Rattlesnakes use three distinct methods of getting around: serpentine crawling, rectilinear crawling and sidewinding.  the first two are common to all terrestial snakes and sidewindingis peculiar to only one in the States.

     Seperntine crawling is the method of locomotion where the snake uses its flanks to push against irrigularties on the surface.  Each part of the snake pushes against the same point of contact in sequence so the tracks, if visable, would consist of parallel-sided wiggle looking trail.  this is the standard method of travle for rattlesnakes.

     Rectilinear locomotion is straight-in-lone crawling, simular to a carerpillar.  Rather than many feet,  the snake used its ventral scales hooking one on some irrigularaty of ground and pulling the next scale foreward.  Then the next scale hooks the same spot and pulls foreward in turn.  This process s going along along the whole length of the snake , so that all times some sections are pulling and others are being pulled.  the effect is a smooth gliding motion and the trackis a smooth straight line.  Large heavy bodied snakes use this locomotion especially when the ground provides no large objests to push against.  all rattlesnake use this motion when moving quietly up on prey to get in striking distance.

     Sidewinding is pereformed by the sidewinder.  It starts by raising its head off the ground and throwing it sideways.  by the time the head has landed, several inches of the body will hqve followed it.  By the time the tail has followed the head had already began a new throw.  The overall effect is the snake is rapidly skimming over the surface in about a 45 degree angle to the line of its body.  Because every part of the body leaves the surface at some time , the track looks like a series of J shaped  marks on the sand.

ACTIVITY PATTERNS

     Like all reptiles, rattlesnakes cannot create their own body heat like mammals can.  They have to rely on outside sources of warmth,  this means directly or indirectly  the sun.  They may gain heat by basking in the sun’s rays or pressing their bodies against objects, such as rocks that have been warmed by the sun.  A burst of sun basking in the sun in the morning may be enough to reach and keep it going through out the day.  As mush as they need the suns warmth they can overheat and  cause death.  Therefore teampture is  the most important factor in a snakes activity, even more so than food.  the rattle snake thrives best at around 86 degrees F.  At tempetures much lower they have trouble digesting food and moving about.  If it gets much higher than this they can die od heat exaustion.

      the fore going information determines their activites.  At colder areas their movements is during the warmer parts of the day.  At warmer they are more active in the evenings and mornings and at night.  this explains why the mountane snakes are usually found on the south facing slopes. 

     This is as far as I am going on this subject you can figgure for your self when they are likely to be about in your area .

NEXT TIME

HIBERNATION, FEEDING, METHODS OF HUNTING, “FINALLY” VENOM AND EFFECTS, DEFENCE AND LASTLT “THE SEX LIFE OF THE RATTLER”

STAY TUNED

discaimer, sorry my damn spell check would not work this time so appoligise for all mistakes hope you could decipher this mess.

ramblingbob

!!!RATTLER!!! chp.2

March 14, 2007

RATTLER

A NATURAL HISTORY OF RATTLESNAKES

                  This is my second chapter on this blog  of “Chris Mattison’s” excellent book on the rattlesnake of the America’s.  Copyright date 1998, distributed by Sterling Publishing Co. of New York.  Any one with a interest in rattle snakes would be well advised to secure a copy for its excellent photographs alone.  Now on to the meat of the discussion

     In review I should have pointed out that the Subcaudal scales mentioned on the tail are located on the lower side of the tail, the top has regular scales.

  SKIN SHEDDING

     Rattlers shed their skin from time to time like all other snakes.  the outer layer called the epidermis is a thin transparent layer that is supple when being shed but quickly becomes brittle after shedding.  Juvenile snakes shed up to seven times in the first year.  Adults can shed three times in a season.  the first shed usually happens in the spring shortly after hibernation.  shedding occurs when a new layer of epidermal is formed under the old one.  They start by rubbing the nose against something hard and rough like a rock, to free the skin from around the jaw area.  then they crawl over rough ground like rock or rouggh vegetaion  until the entire skin is pulled away.  Rattlesnakes differ from other snakes in that the skin that covers the scale of the tail does not shed.

THE RATTLE

     The rattle sets the snake apart from all others, nothing like it is fond anywhere else.  the rattle consists of a series horny shells which fit loosely over one another.  They are made of keratin, the same material that form horn, claws, hair and finger nails.

     Each segment of a rattle originates as the scale at the tip of the rattlers tail.  I wish I had the skill to make a line drawing to illustrate this (but sadly I do not have the computer skill to do this).  The first scale on a juvenile is called a bud and does not rattle, the scale covers the entire tip of the tail and has a bulb like tip.  As the snake shed it’s first skin the bud does not fall off but remains stuck to the new scale.

     In trying to think of a way to explain the construction of a rattle I remembered a magic trick I used to do(One of my many hobbies on days gone by, another chapter later on maybe).  Somewhere around here I have a plastic shell of a thumb which I place over my thumb to do several different tricks.  It fits snuggly over my thumb to the first knuckle, and slips off easily.  This is much the same way the scale at the tip of the rattlers tail is.  Imagine that we take a cord and wrap it around the thumb just below the nail and draw it tight enough to make a indentation all the way around,  Now we have the segment of a rattle.  As the old scale starts shed the base of the scale shrinks  and catches in the groove of the new scale, now it is held in place and is a segment of the rattle, neat huh?   (more…)

Replies to comments on Snakes

September 28, 2006

     I am amazed at the number of hits I get on this blog looking for information regarding snakes.  I am no expert by any means, just like many of you I have a healthy interest and respect for the reptile.  Most of my information comes from books especially the wonderful Peterson Guides.  I gave my better ones to my grandson a number of years ago and sorely miss them now.  To be honest I bought most of them at second hand book stores where you can find great bargains if you will look.

      OK first one person was looking for information about a small thin black snake with yellow stripes on each side.  I have no idea as to the area the person was writing from, but most likely it was a member of the Racer family.  It is a harmless garden variety of garden snake 30″is long for this little guy.  They can travel very fast, and are the most common kind of pet snake.  They tame easily and can be handled gently.  Also they are used in scientific research as they are plenty-full.  I believe in one area of Indiana they hatch in great numbers and flood a particular town.  Not a place for the squeamish to live,  house wife’s sleep them out with brooms and children catch them in droves for resale to labs,  This from a national Geographic article.

        Next one asked about Black Snake rasing off the ground.    Acutally I have read that any snake can raise the frontthird of it’s body into the air.  This is also the distance a snake can strike.  When it coils it’s self up it anchors it’s body with the back two thirds of it’s body, and can strike the distance of the remainder.  There are at least four varities of the black snake.  All are members of the garden snake family, and some can reach 100in length.  Some have a light white stripe on its side and most have a white or cream belly.  These snakes are constrictors and farmers consider the beneficial, as the help control the rodent population on farms.  The diets of all snakes are rodents, insects small mammals and birds, none are vegetarian.

     A quick word about the differences of the Vipers and nonpoisonous snakes.  The first noticeable variance is the head and neck.  A viper has a definite neck and the head is broader than the neck most often wedge shaped.  The American vipers are known as pit vipers because of a very noticeable pit located between the eyes and nostrils. (I know who is going to get close enough to look for nostrils on a dangerous snake).  But the pits are sunken and quite noticable.  The vipers have generally wider body and a blunt tail, where the harmless snake usually has a more stream lined body and a longer narroe sharp tipped tail.  In a John Wane movie his fellow actor wants to know how to tell a hostile Indian from a tame one,  The Duke points to a King Snake and says the same way you can tell the difference between that guy and a Rattle Snake, when you see it you will know.  That pretty well sums it up.  The Coral Snake is located in a pretty much restricted area of the southern states.  It has no neck and the head is the same size as the body.   It does not have the retractable fangs like the pit vipers but has two fixed fangs that are small it needs to basically chew its poison in into a wound.  It is indeed the most poisonous of the American Snakes on par with the Cobra,  but encounters with humans is rare and would need to strike a finger or something small to inject it’s venom. (more…)

A little more on snakes

August 18, 2006

     I had so much intrest in the ramble about the snakes thought I might ramble on a little more….

     I have always had a interest in snakes and turtles and such.  Never got too interested in frogs though, however lizards and salamanders are of interest to me.  I have had copies of the Peterson’s Guides for all categories for years and they are well worn.  Back in he days before I married and owned my old fire engine red 1958 jeep station wagon.  I always carried them in the back in a milk crate with flash light and several days worth of canned beans and a can of brown bread.   The old wagon was the one vehicle love of my life.  It was always ready to go ,two cans of gas and two of water.  I had a small Armalite .22 survival rifle that came all apart and stored in the plastic stock, a good knife and axe.  My sleeping bag was always there and a tarp.  This old boxie wagon was fire engine red and on a whim I painted the wheels a bright deep yellow.  On each door I placed decal of a American Flag and the American Eagle with spread wings cluching the Olive branches and arrows.  Gun racks on the side window behind the drivers seat.  A small offical tax payer  card on the right windsheild.  No one knew what I was but everybody thought I was somebody.  My uniforme was usually green levies and a kaki millitary shiet launderied with the pressed pleats in front and back.  I might add that at this time I was all of twenty-five years old and a little bit silly.    All anyone had to say was lets go and I was on my way.  Anyway I am rambling away from the snakes that are the them of this chapter.

     Of course in my rambles I saw more snakes than the ones mentioned previously.  But let me drift back to my younger day’s  There was a Movie theater called the Roxy on the south side of the town square.  On Saturdays it featured a early afternoon show for the kids at five cents, and it was always packed.  This was where I first heard of and saw Frank Buck, known as Bring Them Back Alive Buck.  He was a famous capture of wild animals for Zoo’s and Circuses.  I watched him catch Python’s and Boa Constrictors, often wrestling them.  Now I know  most of that stuff was all staged with camera crews and people standing by.  The other week I was channel surfing and hit TCM, they were showing a couple of the old Frank Buck Films, and I sat in for awhile for a trip down memory lane.  They were not as impressive as when I was younger but still enjoyable.  Once I discovered the Public Library I read all his books also.  In one while catching in Burma, they had put a small pig in camp in a compound made by driving stakes in the ground six inches apart planning to have it for thanksgiving dinner.  On waking one morning the natives were all excited.  During the night a python has crawled into the pen and swallowed the pig.  In doing so he could not pass back out between the stakes.  So Frank lost his dinner but got a nice big snake. (more…)

Snakes! Snakes? Snakes I have seen and scared the crap out of me.

June 7, 2006

    Every country kid has a few stories to tell about snakes.  Mine are really very few but they all stand out in my memories.   The first was when I was around four years old, I was playing in my yard and suddenly my mother freaked out.  She grabbed me and fled into the house, leaving me there she ran across the street to our neighbor who was a older man.  He came and killed what I believe was a large Black Snake, in a photo I have some where it looks to have been  maybe three to four feet long.  Black Snakes are generally harmless and beneficial to have around, but to a young mother with a small son I guess it was a monster.  The lots in that part of town were rather large and a large drainage canal ran at the edge of our property.  It was a  perfect place for small rodents and other prey to roam.   My next experience nearly stopped my heart.  I was nine years old and once again living on a large city lot we had a large garden plot next to the house it was a dry dusty day.  I was out side barefooted as was our summer custom.  Moving between the house and the garden I caught a rapid movement from the corner of my eye.  Before I could fathom what was happening a small brown snake slithered rapidly from a garden row across the top of my foot and under the house.  My heart seemed to to turn to ice and I could not even move for a short while.  Later that summer My Stepmother and the woman that lived behind us had cut a hole in the back fence so they could move from house to house and my sister and her little girl could play together.  While standing and visiting together at the fence one day a unfortunate Blue Racer happened to to wander into their vicinity.  Rose spied it and screamed, my mother grabed a hoe (more…)