Snakes are obligate carnivores, which means they only eat animal products (meat, and eggs), and do not eat plants. When they eat prey, they swallow it whole, bones, fur, and all. But can they digest the whole animal?
Snakes have very strong stomach acids that can digest most of the animal they eat, including the bones. The only parts that can not digested are fur, feathers, and scales which are excreted fairly intact.
Snakes manage to digest nearly the entire animal (including bones). This is because, unlike humans that only keep their food in their stomach for a few hours; Snakes can digest a single meal for several days or even weeks, depending on the size of the animal.
A week-long digestion with strong stomach acids is enough to dissolve most organic matter.
That said, there are some cases where not all bones are digested completely. In these cases, the partially digested bones are passed as tiny fragments in the feces.
Snakes Swallow Their Prey Whole (Including Bones)
Unlike most mammals, snakes do not chew their food. In fact, they are not capable of chewing their food, even if they tried, because they do not have the right teeth and jaw structure to chew.
Instead, they swallow the prey whole, bones, fur, and all.
When swallowing prey, they almost always start with the head, because it helps the food go down easier. It also keeps the snake from getting hurt by claws or other pointy parts.
How do snakes manage to swallow prey larger than their heads? Well, it all comes down to the special jaws that let them open their mouths super wide.
Unlike humans, a snake’s jaw isn’t stuck together. It has stretchy bands that let the upper and lower jaw move independently.
This allows the snake to open its mouth really wide, as much as 150° or more!
Also, their skin stretches and their skull bones aren’t tightly connected. This lets them eat things much bigger than their heads, sometimes even bigger than their body diameter.
What Kind of Animals Do Snakes Eat?
Snakes eat different prey depending on their species, size, and the habitat they live in.
Some snakes such as the tentacled snake (Erpeton tentaculatum) have a diet consisting almost entirely of fish.
Others such as the common egg eater (Dasypeltis scabra) feed exclusively on birds’ eggs.
Many other snake species (for example, Cottonmouths Agkistrodon piscivorus ) do not have specialized diets and will eat almost any prey they can catch, overpower, and swallow whole.
Snakes generally eat:
- Mammals, such as mice, rats, rabbits, or even small deer
- Birds (from chicks to full-grown adults)
- Amphibians, like frogs, toads, salamanders, and tadpoles
- Reptiles, including lizards and, in some cases, other snakes
- Fish, especially for aquatic or semi-aquatic snakes
What Happens to the Bones Snakes Swallow Prey?
Most of the prey snakes eat have bones. For example, rabbits have a fully developed spine, skull, and limb bones, and birds have hollow, lightweight bones.
However, snake’s bodies have a way of dealing with the bones: they have a very good digestive system and strong stomach acids.
Once the prey is swallowed and makes its way through the digestive tract, the bones do not stay intact for long.
The snake’s stomach and intestines break them down using highly acidic gastric fluids and proteolytic enzymes.
Over a few days to weeks (deepening on the snake species, and prey size), the bones dissolve and are absorbed as nutrients.
Things like fur, feathers, and scales can’t be digested, and are pooped out later fairly intact.
If you ever take time to “dissect” the feces of a snake, you may find feathers and other undigested materials.
Benefits of Digesting Bones
Most predators leave bones behind when they eat, but snakes eat almost the entire animal they catch. Eating bones is actually beneficial for snakes.
Bones aren’t just hard, they’re full of important nutrients that help snakes stay alive.
Bones have:
- Calcium – Keeps bones and scales strong, and also helps nerves and muscles work right
- Phosphorus – Works with calcium to keep bones strong and gives energy
- Collagen – Helps fix and keep body parts in good shape
- Marrow fats – Give energy to snakes so they can go longer without eating
All of these nutrients help snakes stay strong and healthy.
Also, many snakes do not eat very often, so eating the bones helps them extract as much energy as possible from each meal.
Sometimes, Bones Don’t Get Digested Completely
Although snakes have very good digestive systems, they do not always break down all bones completely.
How well a snake digests bones depends on a few things:
- Size and type of prey – Big prey (like rabbits) with strong bones are harder to digest than smaller prey with softer bones (like birds).
- Species of the snake – Big, strong snakes (like pythons and boas) digest bones better than smaller ones (like garter snakes)
- Temperature – Snakes are cold-blooded animals, so they can digest faster in warmer temperatures, and slower in colder temperatures
- Digestion Time – It can take days or weeks for a snake to fully digest food. The longer it takes, the more complete the digestion.
If digestion is interrupted (for example, due to sudden cold weather) the snake may not process every part of the prey fully.
When this happens, the snake might throw up (regurgitate) its food, or it may pass tiny fragments of undigested parts in its poop.
Conclusion
Snakes have exceptionally good digestive systems. When they eat prey, the whole animal goes down their digestive tract, and it is almost completely dissolved, including the bones and bones!
Their way of eating (and digesting) is necessary because snakes do not always find food in their environment.
Consuming the whole animal gives them enough nutrients to survive without food for a while.
Featured image credit: Richard Johnstone (CC BY-NC 4.0)
Sources:
Kathryn Phillips; PYTHON’S DIGESTIVE WORKOUT. J Exp Biol 15 May 2003; 206 (10): 1600. doi: https://doi.org/10.1242/jeb.00343
Tobias Wang, Emil Rindom, The physiological response to digestion in snakes: A feast for the integrative physiologist, Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, Volume 254, 2021, 110891, ISSN 1095-6433, https://doi.org/10.1016/j.cbpa.2020.110891.
Hi, my name is Ezra Mushala, i have been interested animals all my life. I am the main author and editor here at snakeinformer.com.