Professional Herpetoculture for the Pet Trade

A Discussion on Live vs. Frozen Feeder Rodents


After nearly thirty years of feeding snakes, we've formed a few opinions on the subject of fresh vs. frozen foods. It seems the whole world believes that feeding frozen rodents is the perfect solution to all the problems associated with feeding fresh rodents. Well, it's not perfect and there are a few problems with frozen that keepers need to become aware of and to consider when using this food source.

In this article, we'll consider the advantages and disadvantages of utilizing live or fresh-killed rodents vs. frozen rodents as a food source. By the way, when I mention live feeders here, I am really talking about live only with small pinky & fuzzy mice or rats. Larger feeders should be euthanized immediately before feeding to prevent them from biting or scratching your snake (sometimes causing permanent damage or even death)

Pros of Fresh Feeders

The single biggest advantage live or fresh-killed rodents have over their frozen counterparts is simply that they are the freshest food source available. No proteins, vitamins or nutrients have been lost through time spent in the freezer. There seems to be a misconception on the part of frozen enthusiasts that there is no breakdown of these components in frozen, no doubt started by those who market frozen. Don't believe me? Go to your doctor and tell him you intend to raise your new baby on nothing but frozen foods from birth to adulthood and see what he says. Be prepared for a visit shortly after by child services. Also consider that human food gets lots of preservatives and additives designed to offset these losses, while frozen rodents get nothing. If there's no losses, why would profit hungry corporations go to the extra time and expense of adding these? The answer seems self-evident.

Another strong advantage of utilizing live pinkies and fuzzies is that they can be simply dropped in the cage and left overnight with stubborn feeders or new hatchlings. Small frozen rodents will quickly begin to decay and must be removed quickly from the cage if not eaten immediately. Many snakes resent the intrusion into the cage, and may not calm down enough to feed before the item must be removed. Other new babies may prefer to feed at night. This can make use of frozen foods impractical in large collections.

Cons of Fresh Feeders

The most obvious drawback for most keepers is that it simply is not convenient. Most keepers do not have an in-house supply of live rodents and must therefore make regular trips to a source. Many keepers also complain about the expense. The next most common complaint is that the keeper is squeamish about either killing the rodent or even knowing that the rodent was just killed for them.

Well, all I can say on all of that is: "This is your pet and it's your responsibility, so deal with it. It's also inconvenient when the dog wants to go out at 3:00AM, but it's your responsibility as a pet owner to get out of bed and open the door for him. End of story you lazy bum". Buy me a beer sometime and I'll tell you how I REALLY feel about people who don't give their pets the very best care.

However, there is a hidden disadvantage (rarely getting mentioned in comparison). This is that it's possible to transmit certain parasites to the snake via live (or fresh-killed) prey. While a risk, this is actually much less common than you would suspect. Snakes have been feeding on wild rodents for eons, which harbor a far greater range of parasites, and with little effect. Provided feeder rodents are obtained from clean, disease free stocks, it's a very insignificant problem.

Pros of Frozen Feeders

There's really only one advantage to using frozen feeder rodents and that's convenience. Being able store a small quantity of frozen mice behind the frozen lasagna will eliminate a few trips to the store. You might even get a slightly better price by purchasing in quantity.

Some keepers claim that freezing kills off parasites contained within the rodent. While this may be the case for a few species, many eggs can easily survive this process. Besides, would you purchase rodents knowing they contained tape worms eggs and then feed them to your snakes under any circumstances? Taking the extra time to make sure you are purchasing rodents produced professionally, in a clean environment, and from disease free stock is the best way to prevent parasite transmission.

Cons of Frozen Feeders

Earlier in this article, we touched on loss of vitamins, minerals and nutrients during the freezing process. But we did not mention that the length of time spent in the freezer can increase these losses, not to mention cause freezer burn. It is recommended that you obtain the freshest frozen rodents possible. Making the assumption that your store has provided fresh ones can be a mistake, they may have been in the back of their freezer for months (or worse). Many commercial sources for frozen rodents will date each package with the date frozen, a real help in determining freshness.

Now let's talk about problems with the method of feeding frozen. First and foremost, the frozen rodent MUST be thawed COMPLETELY before use. Each year we get several inquiries from keepers who have failed to do this and are having serious medical problems with their pets as a result. We always hold the rodent in the hand, feeling the thickest parts (especially the head) for any cool temperatures which might indicate that it is not completely thawed before feeding.

But remember, over-thawing can be a whole lot worse! Read the label on a package of chicken. See where it discusses the dangers of exposing it to room temperatures? Well, this is exactly what you MUST do before feeding a frozen rodent! And this rodent is complete, with all gut content and bacteria, not to mention urine and feces, while the chicken has been stripped of all such nasties. So here we are, deliberately exposing a tainted piece of meat to dangerous temperatures before happily handing it to our pet. Sound bad? Well it is.

Salmonella and other nasty organisms can develop amazingly fast, and the real danger here is hidden. You happily feed without knowing and suddenly your snake has slimy green feces and is losing weight faster than an anorexic fashion model. Oh, and remember when you had to touch it to see if it was thawed? Now YOU'VE been exposed! Like it says on that chicken package, always wash hands and surfaces thoroughly with disinfectant (including feeding tongs or similar) after use.

Attempt to minimize the exposure to room temperatures. Thaw as quickly as possible, and offer immediately to your snake. Remove uneaten rodents quickly from the cage, in thirty minutes or less. many keepers will use the microwave oven to quickly thaw rodents. We don't recommend this for several reasons: It's easy to overheat the rodent and burn your snake. It's easy to accidentally cook portions of the meat (which reptiles cannot digest properly). It exposes your microwave oven to the same potential diseases as discussed above. many keepers will place the rodent inside a Ziploc bag and thaw in warm water. This greatly increases the rate of thawing and is the preferred method.


While frozen rodents certainly present a convenient food source, the best and safest food source for captive snakes is fresh-killed rodents from clean disease-free stock.

Here at VMS, we utilize fresh feeders for the bulk of our feedings, filling in with frozen only when insufficient numbers of fresh feeders are being produced. All of our rodents, fresh or frozen, are produced here in our facility from clean disease-free stock. We feel this will provide the best quality food items for our snakes, because as the saying goes, "You are what you eat".