What Do Boa Constrictors Eat?

Like other snakes, boa constrictors are carnivorous. This means that they need to eat whole animals in order to survive and be healthy. Because they don’t have legs to help them catch and incapacitate prey, they use their long, muscular body instead — a process called constriction. Contrary to popular belief, when boas constrict their prey, the animal suffers very little because they pass out within seconds (read about the study here).

Boa constrictors rarely eat consistently in the wild, and they have evolved very slow metabolisms to help them survive this. That being said, there is a difference between “survive” and “thrive,” and consistent, reliable access to prey and supervised nutrition is important to helping pet boas thrive in captivity.

What do boa constrictors eat?

Although boas are carnivores, they still require variety in their diet to get the full spectrum of vitamins and minerals that their bodies need to stay healthy. After all, it’s not like they only eat rats in the wild. Wild boas are very opportunistic eaters, and captive boas are well known for eating just about anything you put into front of their face (within reason, and not humans — I’ll get to this later):

  • Rats
  • Mice
  • Young rabbits
  • Guinea pigs
  • Hamsters
  • Chicks
  • Quail
  • Ducks
  • Reptilinks

Pro tip: B. c. nebulosa keepers have observed that this subspecies is particularly fond of bird prey.

Do boas have to eat live food?

Not at all! In fact, most boa keepers feed their snakes frozen-thawed items only, and the snakes do very well on this diet.

Rodents are notorious for injuring captive snakes, sometimes fatally — but only in cases where the feeder was left in the snake’s cage instead of being supervised. If you must offer live prey, keep a close eye on the interaction and remove the feeder if it isn’t eaten within 15-30 minutes.

If the idea of feeding whole animals to your snake makes you squeamish, a company called Reptilinks offers an alternative that contains all the nutrition your snake needs without the rodent cuteness. If you decide to go this route, make sure to buy the links that don’t have fruits/vegetables in them. This addition works great for omnivores, but for carnivores like boa constrictors, it’s just a waste of ingredients.

Otherwise, keep in mind that there is no such thing as a vegan or vegetarian snake. Tofu, while it may tout some great health benefits for humans as omnivores, simply doesn’t provide the nutrition that snakes need. Whole prey items are more than just protein; they are also composed of vital vitamins, minerals, fats, amino acids, etc. – everything that kept the prey item alive also keeps the snake alive. Whole prey items are (when raised correctly) a complete diet. And before you get out the salad bowl, snakes’ digestive systems are literally incapable of processing plant matter. So no matter how many fruits or vegetables you manage to sneak into a snake’s diet, they get zero nutritional benefit.

In other words, if you simply cannot accept the idea of having a pet that eats animals for food, a pet snake is not for you.

Boa Constrictor Feeding Tips

Photo contributed by Jay David

How often do boas need to eat, and how big should the prey be?

Do not attempt to feed your new boa until at least 1 week after you have brought it home. If s/he refuses to eat, check your husbandry to make sure your temperatures, humidity, and other conditions are correct, and then try again the following week.

As a general rule, a meal should weigh no more than 10% of your boa’s weight, or no larger than the widest part of the snake’s body.

  • Newborn-6 months: every 10-12 days
  • 6-12 months: every 10-12 days
  • 12-18 months: every 12-14 days
  • 18-24 months: every 2-3 weeks
  • 2-2.5 years: every 2-3 weeks
  • 2.5-3 years: every 3-4 weeks
  • 3-4 years: every 4-6 weeks
  • 4+ years: every 4-8 weeks

NOTE — Exact meal size is not mentioned in this outline because different boa species grow at different rates, and recommending one size of prey item at a certain point may work for one species but not another. So until we can put together a feeding guide based on snake weight, use the abovementioned metrics to determine the best feeder size for your boa.

You have probably noticed that there is a lot of room for variation within the schedule. Why? Varying a snake’s feeding schedule helps encourage a healthier feeding response, and helps prevent the snake from getting fat due to overeating. This is also because, like humans, different boas need slightly different feeding schedules. Some might need slightly larger prey, others slightly smaller, some more often, some less often. The key to making sure you’re feeding your boa correctly is to keep tabs on its physical condition and adjust meal size/frequency accordingly.

Looking at this schedule, you may also be worried that feeding the snake so infrequently would be starving it. As mentioned earlier in the article, snakes are not built like humans and other mammals — because they have slow metabolisms and they’re cold-blooded, they don’t need to eat often. In fact, it’s healthier for them not to eat often. Studies are showing that slow feeding is one of the keys to boa longevity, and boa keeper experiences confirm this.

What is an appropriately-sized meal?

Boas aren’t built to handle huge prey items like pythons are. After they’re done swallowing, you should only see a very subtle lump in its belly if at all. They’re not very “stretchy,” so when they eat food that is too big for them, it usually causes regurgitation. This is a highly traumatic event that can severely injure or even kill your boa. If your boa doesn’t regurgitate, large prey items can also cause organ damage and will inevitably shorten the snake’s lifespan.

Where can you get snake food?

  • Perfect Prey
  • Layne Labs
  • RodentPro
  • Local small pet store (avoid Petco/Petsmart/etc, as their rodents tend to be the lowest quality)
  • Local breeders
  • At reptile expos

Most snake keepers prefer to buy their rodents in bulk, since shipping costs are expensive (since they’re frozen, they must be shipped overnight) and buying one rat a week can be inconvenient. Save even more money by combining orders with a friend and splitting the shipping cost.

Do not buy prey from chain pet stores like Petco or Petsmart; they have occasional salmonella outbreaks that can infect your snake. Instead, buy from independent local pet shops, or buy in bulk from reputable breeders (this saves money, too).

Red-Tailed Boa Food - boa eating a bird

Photo contributed by Simon Smallhorne

How to feed your red-tailed boa

If you are using frozen-thawed prey, thaw it out in the fridge the night before feeding day. This allows it to thaw slowly in a cold environment, which discourages bacterial growth, same as how you’re supposed to thaw frozen meat. Then about 15-30 minutes before feeding, stick the prey in a BPA-free plastic bag like a Ziploc and submerge in warm, almost hot, water. The body temperature of a mouse is similar to a human’s, so you’ll want the prey to be about 98-100°F before offering it to your snake. You can check the temperature with your temp gun.

Boas use their sense of smell to locate and identify prey, but simulating “livelike movement” is helpful to encourage the snake to strike. Just wiggling it around will do. Do not hold the prey item in your hand — this is a very good way to get yourself bitten by accident. It might seem funny when your boa is just a baby, but it is much less funny when you’re dealing with a 15-20lb adult animal that has wrapped itself around your arm. Instead, use a pair of soft-tipped feeding tweezers.

Do not stun live feeders. Not only is this an inhumane practice, but if/when the feeder wakes up, it may go into “oh my gosh I’m going to die” mode and start attacking your pet.

Don’t handle your boa for 48 hours after feeding, or else it may regurgitate.

Do boas need calcium or vitamin supplements?

Although as obligate carnivores boas should get all of the nutrition they need from the animals they eat, the nutrition provided by feeder rodents is often lower quality than the nutrition provided by wild prey. Some studies have revealed that commercially-bred feeder rodents are deficient in crucial nutrients like vitamin D, which in turn negatively affects the health of the snakes that eat them. There is a risk of developing nutrient deficiency over time even when you buy your prey items from the best breeders.

That does not mean you should start setting mouse traps, however — wild prey often carry parasites and sometimes even poisons. So instead, every once in a while, lightly dust prey items with calcium or vitamin supplement to help fill in the gaps in your boa’s diet.

Here are the best supplements we’ve found to help keep your boa in tip-top shape:

Due to the natural decay of certain vitamin ingredients, supplements should be replaced every 6 months.

Should you feed in or out of the enclosure?

Inside! Many snake keepers claim that feeding a snake inside its enclosure will create a phenomenon known as “cage aggression.” Cage aggression is a myth, and has repeatedly proven to be so. Removing a boa from its home for feedings only stresses the snake out and can result in refusing to eat even when the snake is hungry. Feeding outside of the enclosure can also be dangerous to the keeper because the snake is in food mode and more likely to bite. Again, while this is no big deal with a juvenile, it is much more inconvenient and painful to deal with when you’re dealing with a hungry 8-10’+ constrictor.

If you’re still worried, use a paper towel roll or snake hook to alert the snake that it’s not food time before you reach in to grab it for handling. (More on that in the Handling section.)

Red-Tailed Boa Food - boa eating a rat

Photo contributed by Simon Smallhorne

How do you know if your boa is getting fat/needs to eat less?

As with many pet snakes, overfeeding and snake obesity is a very common problem. The ideal body condition for a boa is square-shaped, with visible muscle definition on its back and sides. If it’s triangular and you can see its ribs, then it’s too skinny. If it’s round, has fat rolls, or you can see round fat deposits along the sides, then the snake is too fat.

For more information on this topic, visit Health: Obesity.

What is erratic feeding, and is it a good idea?

Erratic feeding is a feeding “schedule” with no schedule at all. There is no feeding schedule in the wild, which means that snakes need to be opportunistic predators if they want to eat. That means active hunting and not refusing what they manage to find. When boas are fed erratically in captivity, they demonstrate a stronger feeding response and tend to be more active because they’re “hunting.” You can feed erratically by randomizing the type of prey offered, the size (within reason), how it is presented (live vs F/T), time of day, time between feedings, tongs vs hiding for the snake to find, etc.

Boas are built to go a long time without food, so skipping a meal every now and then won’t hurt — and actually helps prevent obesity. It may seem cruel at first, but this is actually healthier and more natural.

Will erratic feeding make your snake more aggressive? If you are concerned that changing your snake’s schedule will make it more likely to bite or otherwise treat you like food, train it to associate a light touch from a paper towel roll or snake hook with handling time — not food time. Boas are smart enough to know the difference and act accordingly.

What is power feeding, and why is it a problem?

Humans and other mammals have stomachs and digestive tracts that are always ready to eat. It doesn’t matter whether we’ve fasted for 24 hours or are snacking every hour — our stomachs are ready whenever we need it.

However, that’s not how snakes are built. When a snake eats, its body undergoes a radical transformation. The organs change completely, swelling from near-invisible micro-organs to a full-sized digestive tract that can break down bones, fur, and claws. Once the animal has been completely digested and its remains have been passed as waste, then the snake’s digestive organs shrink back down to rest. If digestion is regularly not allowed to complete and the organs not allowed to rest before the next meal, other organs get put under strain, causing immense physiological stress, and lifespan is dramatically shortened.

Will a boa constrictor eat your other pets?

Possibly. There are recorded instances of pet boas eating other family pets. If you have a cat, small dog, bird, or other small, unsecured pet(s) in your home, then yes, the boa may eat it if given the opportunity. In order to prevent this, other pets should not be in the same room while you are handling your boa. Birds are most at risk.

Will a boa constrictor eat a child?

No. Even a newborn human is too large for most boas to consider prey.  Furthermore, there have been no confirmed fatalities resulting from victim being constricted to death by a boa. That being said, exercise caution when your children handle your boa (as with any pet). Do not let the snake wrap around their neck or torso, and never leave them with the snake unsupervised.

Finally — Don’t post feeding videos to social media!

Please do not post your boa constrictor feeding pictures or videos to the Internet — and don’t even share them with friends if they are not snake people. The reptile community has gotten into a bad habit of tolerating and even praising this media, which fuels the widespread fear of snakes and harms USARK’s fight to keep pet snakes legal. (read more about their campaign here). Be a responsible, mature snake owner: Don’t post feeding videos!

New England Reptile wrote an powerful Facebook post on the damage that snake feeding videos can do. There’s some strong language, and it’s a little long, but every bit worth the read. With their permission, I reposted a filtered version to ReptiFiles here.

Red-Tailed Boa Food - boa in water

Photo contributed by Jessie Mcwhorter

Let’s talk about drinking water

Aside from regulating humidity, a large water bowl gives your snake a place to soak, as well as (obviously) stay hydrated. Keep it filled with clean water, refilling daily. Disinfect with an animal-safe disinfectant like F10 or chlorhexidine weekly or whenever the water gets soiled.

There is some debate in the reptile community about the best type of water to put in our pets’ water bowls. I’m not going to go too deep into this, but it’s an important enough subject that it’s worth a quick discussion.

There is a common belief that distilled or softened water is better for reptiles than tap water. This is false. While it is better to use these for misting because they don’t leave mineral residue, the lack of minerals in these types of water creates osmotic imbalance within the snake’s body after ingestion. As a result, the body has to give away its own minerals and electrolytes to restore balance. Over time, this can actually lead to illness.

Tap water, although often villainized by human health sites, often comes from wells and underground aquifers, where the water picks up beneficial minerals like calcium and magnesium. Distilled water and softened water has these minerals removed, the same minerals we try to supplement to our reptiles with powders. Check your local water composition survey first to make sure it’s safe to drink, but in most cases it is perfectly fine to give tap, spring, or filtered water to your snake. 

What is the difference between distilled water and rainwater? When water evaporates from the earth to the sky, it is in its purest form, comparable to distilled water. However as it comes down, it picks up whatever dust or debris may be in the atmosphere, picking up trace amounts of minerals in the process. It will also pick up pollution, so rainwater is unsuitable to provide if your area suffers from air pollution. Distilled water is created through the process of evaporation and condensation, then collecting the condensed water. This is water in its purest form, with no minerals, particles, or anything in it except H2O. Distilled water is not safe to drink because it leaches minerals and electrolytes from the body.

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