Hermit crabs and turtles are pets that can be kept in aquariums. Many assume that the two can get along and live together without considering all the other factors.
Turtles grow to be much bigger than hermit crabs. Does that make them unsafe companions? Hermit crabs need a high humidity living environment. Is that safe for turtles?
Hermit crabs and turtles may share similarities in how they live and the food they eat, but are they compatible enough to live in the same tank and get along?
Can Hermit Crabs Live with Turtles?
While hermit crabs and turtles are often kept as pets in tanks or enclosures, that commonality isn’t enough to say they can live together in one. It’s not as simple as already having a hermit crab tank and deciding to put a turtle in there to keep the hermit crabs company.
These two entirely different species have certain requirements to thrive in captivity, and many of those requirements may not overlap:
Tank Size Requirements
Terrestrial hermit crabs need a tank big enough to move around and have room to dig and explore.
As hermit crabs are social creatures, you should have at least two living in the same tank. You’d need at least a 10-gallon tank to house two hermit crabs.
Turtles grow to be much bigger than hermit crabs. Therefore, turtles need much more space to move around than hermit crabs.
The tank size needed for turtles varies depending on the size of the turtle. Small turtles will need a tank of between 30 and 55 gallons, and larger turtles will need a tank of between 55 and 75 gallons.
A good rule of thumb is to measure the turtle’s shell, and every 1-inch of shell requires 10 gallons of space – so a turtle shell that measures 5 inches across will need a 50-gallon tank.
There wouldn’t be enough room in a hermit crab tank for a turtle. The turtle tank would be big enough to also house a hermit crab, but don’t go putting them together just yet.
There are some similarities in the types of environments that turtles and hermit crabs live in, but differences could make housing them together difficult.
Hermit crabs need 80% humidity to survive. If the humidity is too low, hermit crabs can suffocate and die. This humidity level is also ideal for a turtle’s living environment.
Keeping the humidity level constant is one of the hardest parts of having hermit crabs as pets. It needs to be monitored constantly. Most people use a hygrometer, or a humidity gauge, attached to the tank.
The tank’s temperature needs to be 80 degrees Fahrenheit. A heat pad under the tank can help maintain this temperature without overheating the hermit crabs.
Turtles like shady, cooler areas ranging from 74 to 80 degrees Fahrenheit. They also like basking in warmer, sunnier areas between 85 and 90 degrees, so you’d need a heat lamp for them to bask under.
Heat lamps can be dangerous for hermit crabs because they can emit too much heat that can harm or even kill them. This fact alone would make placing turtles and hermit crabs in a tank together a bad idea.
Hermit crabs need a small saltwater pool and a small freshwater pool. Because land hermit crabs can’t breathe underwater, these two pools need to be shallow enough for the hermit crab to climb out of easily, or they could risk drowning.
Box turtles need a pool of fresh water to drink from. This pool should be big and deep enough to allow the turtle to wade in but shallow enough for the turtle to easily climb in and out.
The water the turtles need may be too deep for hermit crabs to safely maneuver in without drowning. And since turtles drink freshwater, they might get sick if they drink from the saltwater pool that hermit crabs need.
Hermit crabs in captivity can also be fed commercially available pellets that will provide them with essential nutrients and vitamins. They also eat plants, meat, and insects.
Turtles also like to eat things like crickets, grasshoppers, worms, slugs, and snails.
Sand is the ideal type of substrate to use in tanks for turtles and hermit crabs because they both like to dig, and it’s easier to clean than other substrates like pebbles and gravel.
The personalities of hermit crabs and turtles show many similarities.
According to Biology Letters, when hermit crabs feel shy, become startled, or feel threatened, they’ll retreat into their shells and may be slow to re-emerge.
On the other hand, they also have an aggressive side, and sometimes instead of retreating into their shell when they feel threatened, they’ll attack using their claws, such as when they’re in a shell fight.
Similarly, Amphibia-Reptilia states that when turtles feel shy, become startled, or feel threatened, they’ll retreat into their shells, too. Turtles retreat in stages depending on the level of threat they feel.
A mild reaction causes them to partially tuck in just their head. Then, they’ll tuck their head and limbs completely into their shell. At the highest level of fear, they’ll tuck everything into their shell and close their shell off.
Turtles aren’t highly aggressive, but sometimes when they feel threatened, their response might be to bite or urinate instead of retreating into their shell.
Hermit crabs are social creatures, so they’ll often be seen traveling or living in large groups in the wild. In captivity, they have a better chance of thriving if they have at least one companion, though the more there are, the better.
Turtles are just the opposite, as they’re not social animals. They may be seen around other turtles but don’t interact with others.
Hermit crabs love to dig, play, and explore, but they do most of these things during the night, so you’ll rarely get to see them at their most active unless you stay up all night.
Turtles also love to dig and explore, but they’re active during the day. In the wild, they spend most of their day looking for food. In captivity, you might find them splashing in the water, digging holes in the sand, or basking on a rock under their heat lamp.
Do Turtles Eat Hermit Crabs?
As mentioned, turtles have a diet that consists of fruits and vegetables, plants, flowers, grass, crickets, grasshoppers, worms, slugs, and snails.
Although some claim that turtles will eat hermit crabs, it’s difficult to find scientific evidence.
However, the American Society of Ichthyologists and Herpetologists states that the digestive tract contents of Loggerhead Sea Turtles were examined, and remnants of hermit crabs were discovered along with various types of crabs and fish.
Based on this information, it’s safe to say that at least some types of sea turtles eat hermit crabs, which means it’s probably not a good idea for sea turtles and aquatic hermit crabs to live in a saltwater tank together unless you intend for the hermit crabs to be food for the sea turtles.
Can Hermit Crabs Eat Turtle Food?
Hermit crabs have a wide range of things they’ll eat, from fish to plants.
Hermit crabs can eat store-bought turtle food because they’ll eat almost anything. However, turtle food is manufactured for turtles, so it may not contain the necessary nutrients that hermit crabs need.
If you feed turtle food to hermit crabs, it shouldn’t be their sole source of nutrition. They should eat the pellet food designed for hermit crabs and supplemental foods.
Do Hermit Crabs and Turtles Get Along?
Hermit crabs and turtles have many similarities, and their personalities share most of the same traits. They both carry shells on their backs that they live in and use to protect themselves against prey.
Many environmental factors that turtles and hermit crabs need to survive are also the same. Based on those factors, it’s safe to assume they might get along in a tank together.
However, turtles grow to be much bigger than hermit crabs, which would put the hermit crabs in danger of being hurt or killed by turtles in such a confined space as a tank.
Hermit crabs also have needs that are very different from what turtles need, and vice versa. These differences are why hermit crabs and turtles probably shouldn’t be in a tank together.
Since sea turtles eat hermit crabs, a hungry turtle might eat its hermit crab companion at some point.