Hermit Crab Care

Hermit Crab Care Guide

Basic Information

Hermit crabs are fun first time pets for all ages. They have a very social personality and love interacting with people after proper first introductions. However, their husbandry is not considered beginner-friendly so oftentimes it can be intimidating to own them as they have very specific requirements compared to many other animals. Below we’ve included everything you need to get started. 

Health

During the molting process, hermit crabs will bury themselves in the substrate for weeks at a time. It is imperative that they are not disturbed during this time as they can possibly get so stressed they die. 

Hermit crabs are handleable but need time to adjust to their new settings. Leave them alone for a few days until they are more active and out of their shell. Then slowly introduce your hand to them. All hermit crabs are different so some may adjust to you quickly while others may take longer. 

All hermit crabs have a social personality. It is highly recommended to house at minimum 2 hermit crabs together so they have companionship and enrichment with each other. Isolated hermit crabs can become depressed and sickly. 

Enclosures

The general rule of thumb for enclosure size is 10-gallons for 2 hermit crabs, then increase as the crabs get bigger or if you decide to get more. A glass aquarium works best to retain the heat and high humidity needed for hermit crabs along with a secure, screen top for some ventilation. Including the several inches of substrate on the bottom, you can also decorate with some moss and plants along the bottom of the enclosure for some added foliage. Caves are a great addition as well for some security and enrichment. Be sure to also include extra shells that are adequate sizing for the crabs currently in your enclosure. **Please research where to buy or obtain shells from reputable sources; commonly sold painted shells can be extremely toxic and kill your crabs!

Heating/Lighting

There should be a heat gradient within the tank ranging from about 75 degrees Fahrenheit on the cooler end and 85 degrees Fahrenheit on the warmer end. You can use a heat mat on the underside of the tank attached to a thermometer as your best option. Alternatively you can use a well situated clamp lamp with a proper heating bulb. Hermit crabs do not need any additional lighting if their enclosure is in an area that has exposure to some or a lot of natural daylight. Having some exposure is beneficial for a natural circadian rhythm and overall health. If you do need some lighting, you can use a hooded aquarium LED light on a timer for 12 hours on and 12 hours off. 

Substrate

Substrate options for hermit crabs should include sand and coco fiber. It is important to research the brand of sand you use as some contain minerals that are toxic to hermit crabs. Sand with calcium included in it is recommended or pure sand often used with reptiles is another option. Coco fiber is recommended to mix in with the sand for moisture/humidity retention. Pieces of sphagnum moss are an option additional to also help aid with humidity. The enclosure should have a deep layer of substrate, about 3 times the height of the hermit crab to allow for digging and burrowing, especially when molting. Spot clean the substrate daily and fully replace it every few months. 

Humidity

Hermit crabs need high humidity as they breathe through gills that need moisture, otherwise they can suffocate and die. Humidity levels need to be maintained in an 80-90% range. Regular misting will need to be done as well as using moisture retention based substrate to ensure the needed humidity is met. Use a hygrometer to monitor humidity levels. **Be sure to use dechlorinated water for spraying and misting!

Water

Two water bowls are required for hermit crabs. One will need to be filled with fresh dechlorinated water and the other will need to be filled with salt water that is appropriate for hermit crabs like dechlorinated aquarium salt. (1.020-1.023) The bowls need to be easy for the crab to get in and out of, such as a ramp bowl which will allow them to soak however they need to. You can also choose to include sea sponge in the bowls for another way for the crabs to access the bowls as well as another way to retain humidity. Clean and refill bowls regularly. 

Food

There is a wide variety of food that can be fed to your hermit crab. There are commercially available hermit crab diet pallets available that contain a healthy variety of minerals and vitamins that’s necessary for hermit crabs. Plant options include oak and maple leaves that have not been treated with pesticides. Protein options include brine shrimp, krill, and bloodworms. Many fruits can also be offered such as blueberries, grapes, and apples. Be sure to add a calcium supplement every so often as this will help the hermit crabs during their molting process. Feed at night and remove uneaten food daily to prevent bacterial and fungal growth.