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why do tortoises eat stones?

Why Does My Tortoise Try To Eat Stones, Rocks, And Pebbles?

Wild tortoises eat small stones, rocks, or pebbles due to a deficiency in their diet or routine.

Although it’s a normal compulsion, eating rocks isn’t beneficial or safe for tortoises. Even if the tortoise isn’t harmed initially, its health can be jeopardized over the long term.

Rather than allowing a tortoise to eat small stones, you need to identify why it’s happening. Resolving the tortoise’s problem will modify this undesirable behavior.

Is Eating Stones Harmful to Tortoises? 

Ingesting any foreign, non-food object carries risks for a tortoise. Although tortoises commonly eat small rocks and pebbles in the wild, it’s a dangerous habit that shouldn’t be encouraged.

The tortoise’s intestines could develop a blockage, leading to internal bleeding, tears, or full ruptures.

Over time, even minor blockages can result in issues like malnutrition, diverticulitis, constipation, bloating, and gastrointestinal distress.

According to the Journal of Zoo and Wildlife Medicine, malnutrition causes tertiary issues, such as eye and shell deterioration.

Soft-shell tortoise breeds can become injured by sharp pebbles and stones. If you have a soft-shell tortoise, remove any sharp materials, rocks, or stone substrate from the enclosure.

Even if the tortoise doesn’t eat the stones, it may cut itself externally, experiencing bleeding, infections, or permanent scarring.  

Why Do Tortoises Eat Stones?

In cases where tortoises consume rocks, it’s usually due to one or more of these factors:

Aiding Digestion 

Many wild herbivores eat small rocks to break down the tough, fibrous materials they consume.

Of course, animals with large grinding teeth (like horses) or compartmentalized stomachs (like cows) use those tools to help break down their fibrous meals.

Tortoises don’t have teeth or compartmentalized stomachs. So, they may eat small stones and pebbles to help grind down tough food in the stomach.

This behavior isn’t limited to tortoises, as some crocodilians and avian species eat small rocks to crush hard foods, including bones or seeds. However, big animals like the crocodile are better equipped to process the small rocks after they’ve served a purpose.

Smaller animals, like tortoises, are more likely to develop a blockage due to eating small stones.

A tortoise doesn’t need to use rocks to digest food. Most consume small stones when they’re experiencing digestive issues, even if it might create a bigger problem in the future.

Why Does My Tortoise Eat Rocks?

Mineral Deficiency

A tortoise commonly eats small rocks from its enclosure due to a mineral deficiency.

Tortoises are especially vulnerable to calcium deficiency. Once the body acknowledges this mineral is lacking, the tortoise may be compelled to get calcium in any way it can.

Rocks are rich in minerals like quartz, feldspar, mica, amphibole, olivine, and calcite. Calcite is a form of calcium carbonate, which is 40% elemental calcium.

Of course, a tortoise’s digestive system isn’t built to process raw minerals. So, a tortoise can’t glean the calcium it needs to address its deficiency.

According to the British Veterinary Association, mature tortoises given basic feed with no calcium supplements were the most negatively impacted.

Rather than deal with weak bones, soft shells, and escalating issues regarding its overall growth, it’ll eat small pebbles and rocks.

Boredom

Although tortoises live simple lives, they become curious when bored.

If your tortoise’s enclosure lacks substrate to dig, obstacles to climb, plants to hide in and explore, and other enrichment, it’ll entertain itself in other ways.

Tortoises may forage for food by eating rocks, pebbles, or broken pieces of toys.

The best way to prevent this is by offering real food that a tortoise can seek out. Hiding berries, greens, and pellets around the enclosure will give a tortoise better things to eat than rocks.

Habit

If you got your tortoise from another owner, and it was routinely left calcium deficient and bored, it may have developed a habit of eating rocks.

This isn’t easy to resolve, even if you provide supplements and other foraging materials. The tortoise will be used to eating stones and compulsively do so going forward.

In such instances, you’ll need to remove pebbles or stones from the enclosure.

Hunger

Tortoises don’t need to eat every day, but they can still starve if not given regular meals on a set schedule.

So, a tortoise may begin eating rocks as it forages for a meal. Even if you feed your tortoise often, providing too-little food can leave it hungry and eager for more sustenance.

Although rocks can’t sate their hunger, they may still forage on them as a natural compulsion.

Accidents

Avoid putting substrate around food bowls or where you spread treats. For particularly small rocks, the tortoise may accidentally consume them as it’s trying to feed.

Meals can get knocked out of their bowls and onto the floor, or a hidden treat for foraging activities could get coated in small stones.

Pebbles may even get into bowls, leaving the tortoise with no choice but to consume the tiny stones and pebbles with its normal food.  

How To Stop Tortoises Eating Stones

Even if there are good reasons for eating stones, you shouldn’t allow your tortoise to consume them.

In the worst-case scenario, it may require surgery from a vet to remove the stones before they cause further harm. If ruptures or internal bleeding happen, the surgeon must repair the damage and put the tortoise on medication to prevent infections.

Some tortoises recover from this ordeal, while others suffer long-term digestive issues. Death is also possible if an infection develops, an impaction remains untreated, or internal bleeding continues.

So, prevent your tortoise from eating rocks by doing the following:

Remove Stones 

Without rocks, stones, or pebbles, a tortoise can’t eat them. Stone substrate is usually chosen for its draining abilities and the way it mimics the natural environment of some tortoises.

However, it should never serve as the entire bedding since tortoises need to burrow, and humidity levels are difficult to maintain with stone.

Swap out your tortoise’s bedding with other materials to minimize the risk of ingesting stones. Better choices include:

  • Smooth sand and soil mixes
  • Peat moss
  • Coconut coir
  • Fir bark
  • Coconut husk chips
  • Cypress mulch

If your tortoise is outdoors, check over its enclosure for any rocks small enough to fit into your tortoise’s mouth, and remove them.

You can also spread new substrate over the soil to hide or cover any rocks too small to be picked up individually. Often, it’s best to mix substrates to create a base dense enough for digging and hiding.

Tortoise’s Needs

Some tortoises will eat rocks no matter what, but it’s rare. If you ensure your tortoise is well fed and is given enriching toys and equipment, it should only consume food.

Tortoises should be fed plants, flowers, vegetables, and leafy greens. Tortoises love hibiscus flowers, mustard greens, dandelions, and other dark, leafy foods.

This should be paired with powdered cuttlebone or mineral blocks.

Also, provide foraging games that will keep your tortoise busy. You can hide greens or flowers around their enclosure, forcing the tortoise to seek them out.

This can be combined with puzzles and terrain-changing pieces, like short bridges and broad shelters. They’ll encourage natural behaviors, such as digging and hiding, preventing boredom.

Logs, moss, and larger rocks that can’t fit inside the tortoise’s mouth can keep your tortoise active and stimulated so it doesn’t start eating pebbles.