State of Prey

Feeding Live Prey versus Pre-killed | Reptiles

frozen thawed mouse being eaten

At least a few times a month, I get an email regarding live prey and feeding snakes. After much discussion of how to approach the subject, we came to the conclusion that a no holds barred approach would be best regarding the ‘state of prey’. Almost all captive snakes can be conditioned over time to accept and consume pre-killed prey on a regular basis.
It’s worth mentioning that wild snakes, regularly take carrion as is shown by studies done in the field on snake diet. Given this fact, it never ceases to amaze us how many people insist on feeding live prey. Live prey can & sometimes does injure snakes during feeding. This is due to the simple fact that the prey wants to live. As any other living organism would do it attempts to defend itself. Just to be clear we are not talking about Garter Snakes Thamnophis sp. Water Snakes Nerodia sp. or Green Snakes Opheodrys sp. These snakes feed on what is essentially defenseless prey so there is really no concern of injury. We are speaking specifically of snakes that consume rodents.

So why do people insist on feeding live prey? The reasons vary but here’s a list of the top ones we’ve heard over time.

  • The thrill of the kill is what my snake needs.
  • It’s more natural.
  • My snake won’t eat pre-killed.

To each one our answer has been that this is complete bullshit! Rarely, and by rare we mean one out every hundred (probably more) snakes commonly kept in captivity will not convert to eating pre-killed prey if given the time and effort to do so. Most commonly kept snakes are constrictors of the colubridboa, and python families. This means that the snake, when feeding will seize the prey and then quickly wrap coils of its body around it constricting until the prey item is asphyxiated. Studies have shown that each time a breath is taken is exhaled that the snake squeezes tighter. Typically, after the prey is dead the snake will use its tongue to identify the head and then begin to swallow it whole.

In most instances this happens with little to no incident of injury to the snake. Some would say that snakes as a predator are stupid. I don’t believe that. I know for fact that snakes are capable of recognizing those who feed them and take care of them. Laurence Klauber also noted this in his studies on Rattlesnakes. Whether a snake is ‘stupid’ is a matter of personal opinion having nothing to do with actual intelligence for more on this see my article on The Cognitive Reptile. If snakes were stupid, they wouldn’t have survived for millennia. Nature has a way of weeding out the non-intelligent.

That being said, snakes do make mistakes in their striking for whatever reason. They miss; they grab hold of the wrong end, etc., this is not a factor of intelligence. In fact, I would be willing to bet that it was a matter of optical acuteness in some species. So for Lenny Flank to say snakes are stupid is completely wrong.

According to studies I have read on snakes in the wild they form complicated decisions when choosing which prey to attempt eating. Some lay in ambush on game trails letting larger prey that may prove too risky to pass by and smaller prey which would not sustain it pass by as well. Harry Greene covers this in-depth in his book Snakes. Others that are active hunters will go right past the same. Also as I have mentioned earlier snakes have been documented eating carrion. So why take the risk?

Live Feeding

The most common cause of injuries and one which I myself am guilty of, is leaving a live rodent in the feeding enclosure. Now you may notice I said feeding enclosure. I use a separate enclosure to feed all of my snakes. Before jumping up in arms listen to what I am about to say.

This site itself is dedicated to living in a smaller space with reptiles. I am NOT telling you take your 16 foot African Rock Python out of its enclosure to feed rabbits and goats to it. That is just ludicrous and the reason I have to say this is people reading the General Rules have commented on this.

For myself and numerous other reptile keepers it is easily understood that if you feed a snake in its original enclosure you can expect to get bitten at some point. Many people want to argue this with me and to them I will say this. I am not saying that this is an absolute, however it is a very common occurrence within herpetoculture. Therefore I will always encourage keepers to error on the side of judgement and simply feed the snake in a different location other than where it is housed in.

Now then back to leaving a live rodent in the enclosure with a reptile especially snakes. Snakes for whatever numerous reasons will not always take a prey item right away and sometimes they may not even attempt to take the prey at all. Often what happens is that said prey item (mouse or rat) is left in the enclosure overnight with the reptile. Rodents whether they have a high metabolism or what I am not sure but they are hungry constantly. They are also scavengers in the wild and will consume anything that doesn’t eat them first. Whether these rodents are captive bred doesn’t mean anything to the rodent they still retain the natural feeding drive to consume just about anything which may have some nutritional value.

Yes, you can leave say some monkey chow, rodent blocks, or what have you in the enclosure in an attempt to possibly prevent injury to the reptile should it decide to not take the prey item. However this isn’t a guarantee that said rodent won’t tire of the food you left and decide that the reptile would potentially make a tastier snack. This can and has lead to the rodent chewing on and eating parts of the reptiles they are left with.

The injuries resulting from such occurrences have but are not limited to tail loss, spine exposure, and even reptiles being killed outright by the rodent itself.

Let me share with you my experience in this which led me to never feed a live rodent again. I came home on feeding day and prepared all the tubs and buckets that I normally fed my snakes in. I then got the appropriate sized mice from the mouse breeding racks and placed these into the tubs with the snakes. Side Note: Never handle rodents then snakes this generally leads to complications of the snake mistaking your hand for food. This is a painful experience trust me.

At the time of this incident I had maybe a few dozen snakes and lizards so feeding was a process that took a few hours. So the snakes are feeding and I am feeding the other reptiles and invertebrates that I was keeping. I come back and begin to take the snakes out of the feeding enclosures and put them back in their home enclosures to digest their meals. I come to the last bucket and therein discovered to my horror that a mouse was chewing on my rosy boas tail and the snake was doing nothing to stop this.

After dispatching said rodent rapidly (feeding it to another snake) I took the boa out and cleaned it with warm water and thankfully there was not any serious damage a few layers of skin had been chewed away. I put the snake in quarantine to watch for any signs of illness or infection and the snake fully recovered from the injury and went on to live a long healthy life. This of course was not only a horrible incident to have occur but one that also fascinated me and began me thinking on the path of snake behavior. I am no herpetologist or wildlife biologist but I have over a decade of experience with our scaly counterparts so I can safely draw some conclusions on why this might occur. As always if you have your inferences or conclusions please leave us some comments as we are open to hearing your experiences on this matter.

I am under the impression and again I am in no way saying this is a fact; snake tails in most snakes have less nerves in them than the rest of the body and that this is why many snakes when being presented a threat will present their tails when attacked. Not only is this less painful but is also a way to escape as the loss of tail will generally not impede the snake in later life. Not to mention the obvious that a decapitated snake is well, a dead snake.

These incidents of course are given that the reptile in question isn’t hungry at the time. Let’s take a look at what can happen if the reptile is hungry. The snake strikes to capture or subdue the prey item and being non-venomous in nature such as most snakes are will constrict the prey item as stated above and asphyxiate the prey. Asphyxiation occurs through the continual tightening of encircled coils of the snakes body around the prey item.

If said prey is a rodent they have teeth and claws. This goes without mention that the said prey item has a general instinct or healthy desire to avoid death. To do so they will and do resort to biting and scratching whatever has taken hold of them. Rodents teeth continually grow throughout their lifetime and are incredibly sharp as they are often used to chew through the husks of seeds, etc. When applied to the soft tissue of a snake’s body or human finger for that matter we can see these will do some serious damage. Depending on where the snake has grabbed the rodent, said rodent may be able to inflict some very serious injuries to the snake itself.

Converting Snakes to Eat Pre-Killed

Converting most snakes over to taking a dead prey item is something that I hear many people having issues with in the captive environment. I have never personally had this issue. I am sure and have no doubt that there will be and have been the inevitable problem feeder when it comes to the conversion from live prey to pre-killed. Let’s take a look at some options to covert reptiles over to pre-killed.

Today most captive bred snakes are already taking pre-killed prey items so this is generally not an issue when feeding. Some however are being fed live food and for these we want to convert them to pre-killed prey. Ideally these would be what are known commonly as frozen/thawed. Frozen/thawed means just that, the rodent is humanely dispatched typically by way of a gas chamber of some kind filled with carbon dioxide. It is then frozen and shipped out to the various stores who sell them. (We sell frozen mice in our store)

You buy the rodents then bring them home and while still in the plastic bag that they are shipped in you place these into a bowl or large cup or hot water to defrost them. They are generally defrosted when the middle of the rodent is able to be pinched gently and is soft. Then take the rodent and offer it to the snake and let nature takes it course. Sometimes you run into a stubborn feeder which will not take the frozen and thawed rodent on its own. In these cases, moving the rodent about with a pair of tongs will usually illicit a strike from the snake. Which then will lead to the snake eating.

Other Techniques

Every so often there will be a snake which refuses to take frozen and thawed foods. To remedy this what some have done is to do what is called ‘braining’ which is essentially exposing the brain of the rodent. This is obviously a messy process and is for me a last resort.

What I have done and have yet to have any snake outlast my technique and refuse to feed is this.


Put the snake into its feeding enclosure and drop the pre-killed prey in and leave it overnight. If the snake hasn’t eaten feed the prey to another reptile and then try again next week. I have had snakes go as long as six months without eating before they finally gave in and got hungry enough and then regularly fed every time afterwards.

Force feeding is something that I have thankfully avoided somehow over the last decade plus years I have been in herpetoculture. I have seen numerous people talking about how to force feed reptiles, etc., and the fact is this. Unless that individual has more experience than I do and has a proven track record in reptiles I am very leery of following their guidance. Outside of that I would go to a veterinarian and learn first hand how to force feed, after and only after I have truly exhausted all my other avenues. It should be clear now that any reptile could and should be fed only pre-killed prey when it comes to rodent eating species. We would love to hear your techniques that you have used successfully so let us know in the comments field below.