Are Hermit Crabs Nocturnal Or Diurnal? Their Sleep Behavior Explained

Having 500 species worldwide, Hermit crabs live in shallow waters and are social animals. Here, we explore whether hermit crabs are nocturnal or diurnal. Hermit crabs can leave their shells and even swap them for better shells if they get too big for their current shelter or if it becomes damaged. Hermit crabs sleep six to eight hours daily, but is this crustacean nocturnal or diurnal?

Hermit Crabs Are Nocturnal

Most hermit crabs are nocturnal animals and enjoy dark spaces over areas with more light. Because of this, these crabs sleep during the day and become active in the evening. Sometimes, hermit crabs will sleep at night if it is very dark.

Hermit Crabs Sleep 6 To 8 Hours Each Day

Hermit crabs sleep six to eight hours each day throughout the daytime. These crabs sleep during the daytime to conserve energy and avoid predators. They also do this due to possible dehydration. If a hermit crab were to spend long periods in the sun, it might dehydrate and die. This behavior is why they stay covered and sleep during the day, as it is safer for them.

Most predators are diurnal, which is also why hermit crabs rest during the daytime. Hermit crabs bury themselves in the sand or a substrate to avoid daily danger when they sleep. They also sleep under rocks, logs, or thick vegetation in the water. Hermit crabs are nocturnal, so they are active at night when they look for food in their surroundings.

How Do Hermit Crabs Sleep?

Hermit crabs sleep with their eyes closed and are very still. These crabs barely breathe while resting. They also sleep in piles. Hermit crabs are social animals who enjoy living in colonies, in the wild, and in captivity. While digging through the sand, you may find a bunch of hermit crabs clustered together. These crabs often sleep in groups for safety. They may not always be able to fight off predators, but as the maxim goes, “there is safety in numbers.”

Nocturnal Hermit Crabs Sometimes Sleep Outside Their Shells

Hermit crabs can leave their shells if they like. Their shells protect against predators but can also become humid in the sun. If this happens, the crab will leave its shell and bury itself in the sand or substrate where it will sleep. This crab becomes more active when it is humid but will sleep in the sand if the air is holding too much moisture.

How To Wake Your Pet Hermit Crab

Waking up your pet hermit crab may be more complicated than you think. These nocturnal hermit crabs can be difficult to rouse, but there are a few tricks you can use. Firstly, consider placing the crab in a different tank or container. If this does not work, gently shake the crab, tap the shell, or lightly spray water on its face. You could also place the hermit crab on your palm to try and arouse it.

If this does not work, you should stimulate the crab to get it to wake up. One way would be to place another hermit crab in its surroundings that is awake. This method will encourage the crab to start moving and prevent it from becoming too sluggish in the future.

If this does not work, you can bathe your crab in warm water to wake it up. Cleaning a hermit crab in warm water will refresh it and may even cause a trance-like state to help it show some interest. Suppose your hermit crab doesn’t wake up after your attempts. In that case, you should take it to a veterinarian or animal shelter for assistance and advice.

A hermit crab may not wake up because it is under-stimulated in its environment or lonely because these are social creatures. It may also stay asleep because the temperature is not suitable. If your crab sleeps for extended periods, you should consider heating its environment. To safely heat the water in the tank, use a water heater, a room warmer, or even sunlight. Some owners even use a heating pad. Once the hermit crab has woken up, you should offer it food and ensure it has as few disruptions as possible.

Lighting for a Pet Hermit Crab

Hermit crabs are nocturnal and need different light settings for various times of the day. During the day, these crabs need a low-light environment to activate their visual system. Owners can accustom their hermit crab to light over time. First, gradually increase the light sources in their environment by switching on the lights for a few hours each morning and evening. Owners can also place lights over where the hermit crabs usually hide and take cover. At nighttime, the hermit crab’s enclosure should have low light, for which LED lights are ideal.

Enclosure Humidity For Your Pet Crab

Hermit crabs need a specific humidity to be happy and healthy. If their environment does not have the correct moisture level or temperature, the crabs may sleep more or not be as active as they should be. The humidity in their environment should be 70% or higher, and the temperature should be between 65 and 80 degrees Fahrenheit.

How To Tell if a Hermit Crab Is Sleeping or Dead

Sometimes, hermit crabs may stay inside their shells for extended periods. You should never put your finger inside the shell to check whether the crab is still alive. Living hermit crabs use their tail and strong muscles to secure themselves to the wall of their shell. To check if it is active, lift the hermit crab shell by its backside and let the crab dangle. If the hermit crab is live, you can see it tightening its grip on the wall of the shell. If it is dead, it will slip out of the shell.

Nocturnal vs. Diurnal: What’s The Difference?

Navigate to Nocturnal vs. Diurnal: What’s The Difference? for further information about the nocturnal and diurnal phenomenon in various living creatures.

Up Next – All About Hermit Crabs

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• 10 Incredible Hermit Crab Facts
• Male vs. Female Hermit Crab: What are the Differences?

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