Home | Recent Research | Cannibalism and Carrion-Feeding in Rattlesnakes (Genus Crotalus) and Water Moccasins (Agkistrodon piscivorus) – Research Update

Cannibalism and Carrion-Feeding in Rattlesnakes (Genus Crotalus) and Water Moccasins (Agkistrodon piscivorus) – Research Update


Writing in the current issue of the journal Animal Behavior, researchers from the University of Grenada report that female Mexican lance-headed rattlesnakes frequently consume infertile eggs and non-living young after giving birth.  This is said to be the first documented case of cannibalism among rattlesnakes (please see below for my observations, however).  Interestingly, with a sole exception, the females did not consume young that were born alive, even though these remain inactive for several hours after birth, and appear (to us, at least!) to be dead.

Rattlesnakes bear live young, and females use up a great deal of energy and body mass during gestation (they do not feed while gravid).  It is theorized that consuming those young which are dead upon birth helps them to recover their strength.

Rattlesnake Cannibalism in another Species

While working with the comprehensive rattlesnake collection at NYC’s Staten Island Zoo, I had the opportunity to participate in breeding efforts for a number of species.  Most births occurred at night and were not filmed, so I cannot say if females of other species ever consumed non-living young.  However, newly born Neo-tropical rattlesnakes (Crotalus durissus) did consume litter-mates on two occasions.

Hog Fat and other Unusual Snake Foods

Contrary to popular belief, many snakes consume non-living prey (i.e. carrion) in the wild.  The most unusual incident I recall was a note published in the journal Herpetologica…a water moccasin (Agkistrodon piscivorous) was observed stripping fat from a road-killed feral hog!

Of the snakes I have worked with in the field and captivity, moccasins, indigo snakes, black racers and anacondas stand out as taking the widest variety of prey species, and each engages in cannibalism.  One particularly large moccasin I cared for consumed a northern water snake that shared its exhibit (not my idea – I had moved on by then!!).  I’m sure the same occurs in the wild, in areas where moccasins and various water snakes co-exist.

A Collection for Rattlesnake Aficionados

I had the wonderful opportunity of participating in the renovation of the Staten Island Zoo’s reptile house, former stomping ground of legendary snakeman Carl Kauffeld (known to all snake keepers as the author of Snakes, the Keeper and the Kept and Snakes and Snake Hunting).

As in former times, the zoo now boasts an impressive rattlesnake collection…please visit if you have the opportunity.  Pictured here are a few exhibits that I set up for the opening – Neo-tropical rattlesnakes, banded rock rattlesnakes and desert Massasaugas.

Further Reading

Lance-headed rattlesnake photos and natural history information are posted at:





  1. avatar

    That is very interesting, I wonder if other live bearing species also consume slugs (dead young.)

    For those of you living West of the Mississippi, check out The American International Rattlesnake Museum in Albuquerque New Mexico. They have the largest collection of different kinds of live rattlesnakes in the world. All are very nicely displayed and well taken care of.

    • avatar

      Hello Jen, Frank Indiviglio here.

      Thanks for your comment, nice to hear from you again.

      Other rattlesnakes have not been observed to feed on still-born young, but I wouldn’t be surprised if they did. I can’t say for certain concerning those I’ve bred in zoos, as it was usually several hours after birth when I first came upon the young. Same as to other live-bearers that I’ve had breed in zoo collections – anacondas, various boas, eyelash vipers, water moccasins.

      Other live-bearing species have not, as far as I know, been reported to do so either, but again one would need to observe the birth in person or on camera to be sure. I’ve bred a few in my own collection (i.e. tentacled snakes, green and northern water snakes, various garter snakes, ribbon snakes, DeKay’s snakes) and in several cases was present at or just after a birth, but I always removed still-born young quickly.

      Yes, the Rattlesnake a Museum is well worth a visit. In the East, the largest rattlesnake collection would, I believe, be that at the Staten Island Zoo. In Carl Kauffeld’s heyday the zoo exhibited all rattlesnake species known at the time…I was lucky enough to have been around for that – sadly, no photos (camera’s were a bit more cumbersome way back then!).

      Any related info that you come across would be most appreciated.

      Thanks, best regards, Frank Indiviglio.

  2. avatar

    Interesting stuff. On http://www.fieldherpforum.com their have been a few posts documenting cottonmouths eating roadkill frogs.

    • avatar

      Hello Joseph, Frank Indiviglio here. Thanks for the comment and link.

      I believe cottonmouths are more likely than other species to take carrion and to try novel items. Years ago I kept a pair of adults in an exhibit with green treefrogs. The snakes always began moving about in “search mode” a few minutes after I tossed in crickets for the frogs to eat. The frogs were always well out of reach – the snakes seemed stimulated by the new scent.

      Interestingly, American roaches that lived in the exhibit also appeared when crickets were thrown in, and I actually saw a roach catch, kill and consume a cricket (roaches were formerly classified in the same order as mantids, and have similar mouthparts, but this was a new observation for me).

      More on unusual snake meals…recently received word of the following photos circulating on the net – a Texas indigo snake consuming a Western diamondback rattlesnake and an olive python that consumed a Maltese dog that weighed only 40% less than the snake itself.

      Best regards, Frank Indiviglio.

  3. avatar

    I am trying to research how to care and feed a baby rattlesnake. My husband caught a diamond head baby yesturday. He would like to keep it if it is possible but will let it go if not. The pet store said they suggest thawed out pinkie mice. Please can you offer any knowledge that would allow us to keep this snake or should we let it go? We would take it to an appropriate place so hopefully no one would later get bit.
    Thank you,

    • avatar

      Hello Suzette, Frank Indiviglio here.

      Please do not attempt to feed or handle the snake! I suggest you call your state wildlife agency (Department of Environmental Conservation or similar) and request that an expert pick up the animal and release it in an appropriate area. Please let me know in which state you are located if you need a phone number.
      Newborn rattlesnakes possess venom which is, drop for drop, more toxic than that of larger animals, and are fully capable of delivering a fatal bite. Even if you or your husband were well acquainted with emergency first aid and were able to receive antivenin in time, massive tissue loss (the flesh is literally “digested”) and permanent paralysis, along with a severe infection and possible “serum sickness” (many people are violently allergic to antivenin) would be likely. The pet store employee was extremely irresponsible in not so advising you. The keeping of venomous snakes is also a felony in most states, and collection is usually prohibited by conservation laws as well.

      I have worked with venomous snakes in zoo collections for over 20 years and can assure you that someone will be bitten in time if you keep the snake. It happens even to well seasoned professionals…the strike comes without warning, and cannot be avoided – if you are in range, you will be hit. Be especially careful to keep your hands away from the screen cover of the terrarium, or any other openings, as a fang can easily fit through such areas. There are other dangers as well…I once received a dose of venom in my eyes after a confiscated diamondback at the Bronx Zoo struck the screen top of its terrarium, spraying venom in the process.

      Diamondback rattlesnakes are particularly high strung and bite readily, and make very poor captives even in zoos. They account for a high percentage of the 7,000+ venomous snake bites recorded in the USA each year. Please take my advice seriously and contact your state wildlife agency.

      Best regards, Frank Indiviglio.

  4. avatar

    My husband believes a rattle snake struck at him tonight, is it possible the venom got in his eye? he was not bitten, but his eye is burning, what should he do?

    • avatar

      Hello, Frank Indiviglio here.

      Rattlesnakes are not able to eject venom through the air and into one’s eyes…only spitting cobras are capable of this. However, if there is any chance that your husband had venom on his clothes (i.e. if the snake bit a shoe or pants leg) and that after contacting this he rubbed his eye, then he should immediately go to the nearest emergency room.

      Good luck and please keep me posted.

      Best regards, Frank Indiviglio.

  5. avatar
    christine adams

    Hi Frank,
    I know that rattlesnakes are extremely dangerous, but it seems that my peers believe it is acceptable to keep them as pets. My room mates boyfriend left one at my house for 3 weekends without feeding or watering it, it was a baby, only had 2 rattles. The snake became more and more worrisome as time went on, it came to the point that one could not step into the room without it rattling, even though its cage was covered with a sheet. I gave them an ultimatem, when i saw the snake was still not being cared for i let it go. (I continued to provide it water, but i did not feed it) Now they are arguing that a rattler can be kept for 3-4 weeks without eating and be fine. OK, well my response to that is how do you know when the last time it fed before you put it in a cage? One article cited (or rather regurgitated) by one of the boys said “Domestically raised rattlesnakes will survive when fed only once a year, but in the field, snakes usually feed more than once, depending on the size of prey consumed.” I don’t know his source as he did not cite it. I am extremely aggravated by their anger at me for releasing “his pet snake”. Can you please settle this debate by telling me how often a rattler of that size should be fed? What the requirements it may have besides simply giving it “pinkies” (which i know would not suit it), such as vitamins etc. And why a rattlesnake should not be kept as a pet, besides that it is life threatening and possibly a felony?
    Thank you very much sir, i look forward to your reply.

    • avatar

      Hello Christine, Frank Indiviglio here.

      Thanks for your interest in our blog. You raise a very important point. Venomous snakes should never, under any circumstances, be kept as pets. I’ve worked with venomous snakes in zoos for decades, and can tell you that even with advanced training and the proper equipment and safeguards, keepers get bit. Amateurs/hobbyists invariably underestimate the dangers, and despite almost universal bravado (usually by young men), they cannot possibly gain the experience and training that is needed. (I should say false bravado – I’ve responded to 10-12 snakebites in my time, all in private collections..and none of the victims kept up the brave act for very long!!).

      Even if antivenin were immediately available, which it is not in the case of pets, permanent nerve damage and actual complete loss of tissue, flesh and organs/appendages is common. Death is a real possibility, even with a small snake – there is evidence that their venom is more potent than that of adults, to compensate for the small volume injected.

      Snakes, venomous or tame, never, ever become domesticated, nor do they respond to certain people favorably, despite the insane stories that may be posted on the net. Captives of 40-50 years have and will bite people, often keyed by circumstances that we cannot sense or understand (chemical ques, disease, vibrations, etc.).

      The argument is made that there are hobbyists who are seriously interested in studying snakes. In my experience, this is rare among those who keep common species, its more of a thrill, or passing interest. Such folks with serious interests have thousands of interesting, harmless species to choose from, or they can seek education and employment as herpetologists.

      Wild-caught snakes always have parasites; the stress of captivity worsens their effect and always causes illness after time; private vets will not, of course, treat venomous snakes, so the outlook for pets is dim.

      As you suggested, length of time without food depends on the last meal, as well as age, activity level, health., temperature etc. Snakes can fast for long periods, but generalizations are not possible. Mice, without vitamins etc., so form a complete diet, but this is a moot point.

      Another serious concern is the fact that you were put at risk due to your concern for the animal. You could have easily been bitten while watering or releasing the snake. Bites can happen even through screening – I once had venom sprayed into my eyes when a rattler struck at the screen top of its terrarium (at the Bronx Zoo). Amateur snake keepers tend to rely on readily available articles dealing with “strike distances” and such in working with their snakes. Thos is a serious mistake, as there are a great many variables that cannot be accounted for in a generalized article

      Please let me know if you need any further information. Good luck, enjoy and please keep me posted.

      Best regards, Frank Indiviglio.

  6. avatar

    Hello Frank,

    Just wondering what kind of training goes into keepers before they are allowed to work with the venomous in a zoological collection? I have observed people handling venomous snakes on several occasions. One was a Ph.d candidate at a university doing a display at a reptile show with various exotic venomous. In many cases a good bit of stock was put on the fact that certain animals were tame. A restless taipan managed to fall off the hook it was climbing onto the floor a few feet away from front row several times during the presentation by the Phd candidate-after which he managed to sweep the squirming creature up with the hook. It seems to me that if for some reason that snake had gone beserk it could have easily shot into the crowd, or even through the hastily placed barriers into the show tables-and who knows what kind of madness that would have started. Now-their certainly isn’t a risk free way of handling even the most docile of venomous snakes-and it is difficult to stay out of strike range at all times such as when lifting them out of a box…but I must say I scratched my head a bit afterword.

    Oh, also is there a way of viewing all comments posted since, say, a last visit? Instead of just the newest ones?


    • avatar

      Hello Joseph, Frank Indiviglio here.

      Nice to hear from you again. Zoos vary, but in most it’s a matter of first using hooks to work with non-venomous snakes, eventually moving on to fast moving species that are hard to deal with. Then the trainee would work for a time with an experienced keeper, and would learn to deal with both daily and emergency situations (dropping snake on floor, co-worker bitten, self bitten etc. In well-run collections, venomous snakes exhibits are ot opened unless at least 2 people are in the building, and snake bite alarms are located within easy reach at all times. Snakebite drills are conducted regularly (including police response, trip to hospital, etc.).

      Students have no such limitations, and, at least in my experience, often get in over their heads. I would never handle a taipan in the situation you describe; a snake that “rides easily” on the hook, and which does not move all that quickly when dropped (many rattlers, copperheads, tree vipers) would be my choice;,and a secure barrier would be in place.

      Yes, you are correct – “madness”…I once saw a woman knocked unconscious when an alligator suddenly burst from its crate during a class, had to save a child from being trampled when a fruit bat fell from its perch in a zoo building, and so on….

      I’ll check with the computer folks concerning your other question, I’m useless in that area….

      Please let me know if you need any further information. Good luck, enjoy and please keep me posted.

      Best regards, Frank Indiviglio.

  7. avatar

    thanks for all your insight. I live in sw Colorado and seem to have a snake problem. I have seen 3 baby rattlesnakes in the yard and don’t know what to do about it. I have kids and pets so im worried about it. can I assume their mom is close by. I don’t want to kill them but I don’t want them so close to the house.

    • avatar


      Thanks for the kind words. Unfortunately, it’s very difficult to deter snakes if they inhabit the surrounding area, but each situation is unique. Contact your state wildlife agency and check for approved nuisance wildlife control people (preferable to searching ads online, etc). Someone experienced in reptile removal would also be able to suggest ways of reducing the likelhood that snakes will take up residence near your home.

      Accidental bites are rare (most occur when people handle snakes, etc) but of course children are a concern. Your doctor should be able to provide information concerning emergency care, phone numbers to have on hand, etc., just so that you are prepared. Please let me know if you need further info.

      best regards, Frank

About Frank Indiviglio

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Being born with a deep interest in animals might seem unfortunate for a native Bronxite , but my family encouraged my interest and the menagerie that sprung from it. Jobs with pet stores and importers had me caring for a fantastic assortment of reptiles and amphibians. After a detour as a lawyer, I was hired as a Bronx Zoo animal keeper and was soon caring for gharials, goliath frogs, king cobras and everything in-between. Research has taken me in pursuit of anacondas, Orinoco crocodiles and other animals in locales ranging from Venezuela’s llanos to Tortuguero’s beaches. Now, after 20+ years with the Bronx Zoo, I am a consultant for several zoos and museums. I have spent time in Japan, and often exchange ideas with zoologists there. I have written books on salamanders, geckos and other “herps”, discussed reptile-keeping on television and presented papers at conferences. A Master’s Degree in biology has led to teaching opportunities. My work puts me in contact with thousands of hobbyists keeping an array of pets. Without fail, I have learned much from them and hope, dear readers, that you will be generous in sharing your thoughts on this blog and web site. For a complete biography of my experience click here.
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