Reptiles are so different from us mammals. They’re covered in scales, are cold-blooded, and lay eggs. Some reptiles even eat rocks. Even though we could never imagine digesting a rock, for some of our scaly friends, this behavior is totally normal.
So, why do reptiles eat rocks?
Some species of reptiles eat rocks on purpose to aid in digestion, adjust buoyancy, or address a mineral deficiency. In captivity, reptiles may also accidentally ingest a rock in their enclosure when mistaken for food. Not all reptiles eat rocks but alligators, crocodiles, and turtles frequently eat rocks.
In this article, we’ll explain all of the reasons why reptiles eat rocks. We’ll also talk about which reptile species regularly eat rocks and which don’t.
Why Do Reptiles Eat Rocks?
It’s crazy to think that some animals eat rocks, and like it! But, there are plenty of examples of reptiles who need to eat rocks so that their bodies function. In the wild, it’s normal to find corpses of certain reptiles with rocks in their bellies. If you’ve ever owned a pet reptile, you know they might eat a rock here or there.
Now, eating rocks isn’t normal for all reptile species and in many cases can be incredibly problematic. Down below we’ll talk about the reasons why certain reptiles might eat rocks and if it’s healthy or not.
Reason 1: To Aid In Digestion
One of the biggest reasons that animals eat rocks is to help them digest food in their stomachs. It’s so common for animals to eat rocks for digestion that these rocks have a special name; gastroliths.
Gastroliths are rocks or stones that are retained within the gastrointestinal tract of an animal. For animals that don’t chew their food, these stones can help to grind up food. It’s agreed upon that dinosaurs were one of the first recorded animals to use gastroliths. Fossil records show clear evidence that these scaly beasts ate rocks.
Today, it’s believed that crocodiles and alligators might be some reptiles that ingest stones to help them digest food.
Reason 2: To Help Adjust Buoyancy
Another huge reason why reptiles might ingest rocks is to help adjust their buoyancy. For reptiles that live in freshwater or saltwater, proper buoyancy is essential.
Buoyancy is a difficult concept to explain. It’s basically the forces that push against you when you try to submerge yourself or something in the water. Scuba divers use weights to adjust their buoyancy so they can descend into the water faster.
It’s still a source of debate as to whether or not marine mammals use stomach stones to sink or to help with digestion. One thing that’s sure is that rocks are denser and more effective at sinking than bone.
Reptiles that are known to use rocks to adjust their buoyancy by eating rocks are crocodiles and alligators. These reptiles spend the majority of their lives in fresh and salt water. Eating rocks may help them sink into the depths much easier.
Reason 3: To Address A Mineral Deficiency
Mineral deficiencies are more common than you may think for captive reptiles. One of the reasons why both humans and animals eat rocks historically is to correct a mineral deficiency.
What you may be observing in an animal that eats rocks is actually pica. Pica is a condition that occurs due to a nutritional deficiency. Pica describes a behavior in which an animal eats inappropriate objects and indigestible objects.
Some animals with pica may eat rocks to correct iron or magnesium deficiencies. Even though it’s explainable, pica is not a good thing. If your captive reptile is eating rocks because their mineral deficient, there are many problems. For animals that shouldn’t have rocks in their stomachs, this is a medical emergency. Rocks in a reptile’s stomach can cause bowel obstructions and painful defecation.
Reason 4: Accidentally In Captivity
The last reason why reptiles might eat rocks only applies to captive reptiles. Some pet reptiles may accidentally ingest rocks while in their enclosures.
Rock and sand ingestion is a serious issue for reptiles. Reptiles may either become confused or accidentally consume rocks with their meals. this is very common in insectivorous lizards who hunt small, fast, bugs. The lizard might lash out at a prey item and snatch it up with its mouth. Naturally, that reptile might pick up a few small pebbles during the hunt.
Some animals are more prone to accidentally eating rocks and sand than others. It’s important to consider this when picking out a substrate for your pet reptile. Even though sand and small rocks seem like the perfect substrate for something like a leopard gecko, it often leads to impaction or bowel obstruction.
You can see in the video below what some of the signs are for impaction and what you can do if your reptile eats rocks and becomes impacted. Our first recommendation is always to consult your veterinarian.
Which Reptiles Eat Rocks Regularly?
As you’ve probably noticed by now, it’s not normal for most reptiles to eat rocks. With some exceptions, if you see your pet reptile, eating a rock, it’s an issue. We’ll go over each group of reptiles below to tell you whether or not it’s normal for them to eat rocks.
Do Lizards Eat Rocks?
Some larger lizards may swallow rocks to help them digest food. However, it’s not completely normal behavior, and you should always take note if your pet reptile is swallowing rocks.
Smaller species of lizards like crested geckos, and leopard geckos don’t seem to eat rocks purposely. Some sources say that larger lizards like bearded dragons and iguanas may eat rocks.
Do Turtles And Tortoises Eat Rocks?
It’s common for turtle and tortoise owners to observe their pets eating rocks. While it might seem like this could be a natural behavior for them, it’s not. If your turtle or a tortoise is eating rocks, it means they could have a mineral or nutritional deficiency.
Turtles commonly eat rocks because they don’t have access to the diets that they need. Husbandry and diet are so important for making sure that your pet reptile lives a long and healthy life. Make sure to look up the species-specific requirements for feeding your pet turtle or tortoise.
Do Snakes Eat Rocks?
Snakes are one group of reptiles that definitely don’t eat rocks. Snakes have complex digestive systems that are built to break down whole prey. They don’t need any help from rocks for this process.
Snakes also have a really difficult time passing a rock through their bodies because of their extremely long digestive tracts.
In captivity, if your snake eats a rock, call your veterinarian as soon as possible. Though they may be able to pass this rock with a little bit of help, it could turn into an issue.
Do Alligators And Crocodiles Eat Rocks?
Alligators and crocodiles are one of the few reptile species that are regularly observed eating rocks. It’s thought that these large reptiles eat rocks both to aid in digestion and to help buoyancy.
Many alligator and crocodile carcasses have been necropsied and stones have been found within their stomachs. It’s no surprise that these giant and tough reptiles are able to consume rocks and be perfectly fine.
Do Any Other Animals Eat Rocks?
Birds are probably the number one example of animals that eat rocks. Most birds have a crop or a gizzard that helps them digest food before it enters their stomach. The crop is incredibly muscular and is often filled with rocks. This crop acts like a grinder to crush up seeds and insects to make them easily digestible for the bird.
In the wild, reptiles do all sorts of things to live their best lives. One of those things, oddly enough, is eating rocks. Crocodiles and alligators are known to eat rocks to help them digest food and to dive deep underwater. Some large lizards are also known to eat rocks to help them digest bugs and other food items.
In captivity, it’s usually a concern if your reptile is eating rocks. It probably means that they’re experiencing some sort of nutritional deficiency or they’ve done it by accident.
If you see your reptile ingesting rocks make sure to give your veterinarian a call. Though it may be “normal “behavior for some species, you don’t want to deal with a rock, causing an impaction for your scaly friend.