Why is my Turtle Eating Rocks

If you’ve noticed your pet turtle eating rocks occasionally, you may be wondering a few things,  the biggest one probably being—why?

Believe it or not, this is actually a fairly normal occurrence for both turtles and tortoises alike, so don’t worry; your amphibious friend isn’t the only one.

In this article, we’ll go over all the details so you gain a better understanding of your pet’s seemingly odd habit. 

Why Is My Turtle Eat Rocks? 

In the wild, turtles are known to consume rocks and pebbles for various reasons, the main one being that they crave certain minerals that can be found in them.

While they won’t pig out on them, the occasional stone snack can be beneficial for a wild turtle.

Although in captivity, your turtle should have important minerals supplemented, so if your pet is getting the urge to eat the rocks on the bottom of its tank, it may be a sign to up their supplement intake. 

Animals such as crocodiles and some birds are known to eat rocks and stones purposefully as well, which can help to crush and grind tougher foods such as bones and seeds throughout their digestive tract.

It’s likely that part of the reason that turtles do this is for similar reasons, although that still doesn’t mean your pet should at all be encouraged to do so. 

While the odd pebble, here and there, isn’t likely to cause much harm, it also isn’t necessarily good for your pet turtle to be consuming them.

If they eat too many, it could cause serious digestive system problems.

Since a big part of the reason turtles in captivity eat rocks in the first place is boredom, they’re more likely to overeat.

Overall it’s best not to let your turtle eat any rocks, as it will most likely cause more harm than good. 

Nutritional Value of Rocks

Though they’re not something you would expect to hold nutritional value, certain rocks do have vitamins and minerals that turtles can benefit from.

Iron and calcium are two great examples,  both of which are important to your turtle’s wellbeing.

Providing your pet with something like a cuttlebone is a much better option though, offering the minerals that they’re craving while not wreaking havoc on their digestive system.

Below we’ll list different minerals found in rocks that are of importance to your pet turtle. 

  • Iron 

Feeding your turtle dark leafy greens is a great way to ensure they’re getting enough iron

  • Calcium 

To keep their bones and shell healthy, turtles need a good amount of calcium in their diet.

Feeding them calcium-rich foods is a great start, but it’s also a good idea to feed them a  calcium supplement as well 

A lack of calcium could result in metabolic bone disease.

  • Phosphorus

Phosphorus is also important for the health of their bones and shell 

To ensure your turtle is consuming enough phosphorus, provide them with an appropriate  turtle supplement

Turtles in the wild may consume rocks as a way to get enough vitamins and minerals, but a pet turtle should almost always have a supplement to ensure this.

It’s much safer and a lot more effective than pebbles, which aren’t a reliable source of nutrients.

Not only that, but the types of stone in your turtle’s terrarium may not even contain all the good stuff they’re looking for in the first place.

For a healthy pet turtle, a well-balanced diet should include supplements, not rocks or pebbles. 

Are Rocks Bad For Turtles? 

For your turtle’s health and safety, the best answer to keep in mind for this question is yes.

Even if one or two small pebbles may not cause them any harm, you don’t want to figure out where the line is drawn by your pet ending up with some terrible digestive issues.

If the rock they eat is too large, they may require surgery to have it removed.

If you didn’t witness them consuming the stone, it could be a confusing guessing game as to why your pet is acting strange.

One telltale sign is if they’re suddenly refusing to eat, so keep that in mind if you suspect your turtle has eaten a rock. 

Other problems can arise when using pebbles as a substrate for the bottom of your turtle’s tank,  such as injuries if they’re soft-shelled.

While it’s a lot less likely for your pet to get hurt this way if they’re hard-shelled, it’s still best to avoid pebbles in your turtle’s terrarium altogether.

Using fine sand is a great option, as this eliminates both the risk of injury as well as consumption. 

Alternatively, if you’re only worried about your turtle eating the pebbles, you could use large rocks on the bottom of their tank.

This way, they won’t be able to eat them as they’ll be much too large. 

Types of Rocks and Their Effects on Turtles 

A large part of the reason turtles eat rocks in the first place is for the minerals, so different types of rocks could have different effects on the turtle depending on which minerals are found in the

rock. Limestone and Dolomite, for example, are high in calcium, so theoretically, if your turtle were to consume any kind of stone, these would be among the best.

Limestone isn’t a great choice for your turtle’s tank though, as it could affect the water’s pH.

Remember that it’s still ideal to avoid having rocks as a part of your turtle’s diet at all.

In the wild, turtles would consume the occasional small pebble, although it would be more of a guessing game than anything else with no real way for them to know the level of minerals and vitamins inside. 

If your pet turtle does eat a rock, it would ideally be on the smaller side so it’ll pass through their digestive system easier.

The larger the rock, the more likely it is for a problem to arise. 

Types of Substrate Used in Turtle Terrariums 

Large River Rocks 


Smooth river rocks are a popular option to use 

Affordable and easy to come by 

Classic look for a terrarium 


Can be difficult to clean 

May damage the shell of a soft-shelled turtle 

Is only safe to use if rocks are larger than your turtles head 

Pool Filter Sand


Different than regular sand, pool filter sand is a safe and visually appearing substrate  Mostly easy to keep clean 

Offers enrichment 

Very low impact risk for soft-shelled turtles that like to bury themselves 


Can be hard on filters 

A breeding ground for certain anaerobic bacteria 

Still has a slight impaction risk 

Bare Bottom 


  • Very easy to keep the tank clean 
  • The safest option for your turtle 
  • Can easily and quickly scoop waste from the bottom of the tank 


  •  Not very visually appealing 
  •  Lacks enrichment for your turtle 

Choosing the right substrate for your turtle’s terrarium requires a fair bit of effort and research,  and each option has both pros and cons.

Depending on your turtle, any one of these could be a great option.

As a general rule of thumb, it’s important to remember that if you’re going to use rocks in the terrarium, they should be larger than your turtle’s head to prevent them from being consumed. 

FAQ’s About Turtles and Rocks 

Q: Why is my turtle eating rocks

A: They may be lacking certain minerals in their diet, or it could just be boredom 

Q: What should I do if my turtle has eaten rocks

A: If it was a small rock, keep an eye on your turtle to make sure they aren’t showing any signs of a blocked digestive system. If it was a large rock, you may have to take them to an exotic vet 

Q: Is it okay to use rocks in my turtle’s terrarium

A: As long as they are larger than their head and properly cleaned first, yes it is okay to use rocks  in their terrarium 

Q: I think my turtle may have eaten rocks but I didn’t actually see them do so, what should I do

A: If you suspect your turtle may have consumed some rocks, keep a close eye on them to see if they’re still eating and having bowel movements. Remove all rocks from their terrarium as well,  you don’t want them eating more and making the problem worse 

Q: How do I clean rocks before putting them in my turtle’s terrarium?

A: Boiling them in plain water for 10-15 minutes is an appropriate way to clean them for use in a  turtle terrarium 


While little pebbles may be visually appealing in your turtle’s terrarium, it’s best to avoid them for the safety of your pet.

Consumption of rocks could mean a trip to the vet, and if not treated,  could be fatal.

Even though wild turtles are known to consume them, it doesn’t mean that it’s safe or ideal; supplements for your pet are available and are a much better option to ensure they’re getting the necessary vitamins and minerals.

Rocks just aren’t worth the risk, so do your pet turtle a favor and swap them out for another substrate if you haven’t done so already. 

Also read

What Sounds Does a Turtle Make?

Do Turtles Sleep?

Do Turtles get Lonely, bored,depressed or have feelings? (Find out here)

Can Turtles See in the Dark?

Leave a Comment