Last Updated on September 2, 2023 by Joanne Harper
Hermit crabs are omnivorous animals, eating vegetables, fruit, nuts, meat, and fish. If you supplement a hermit crab’s diet with insects, offer pre-killed and frozen bugs.
Insects have various tastes, but most hermit crabs prefer to eat fruit and plants. Bugs are okay as an occasional snack, but they’re not a primary source of nourishment.
Can Hermit Crabs Eat Insects?
Hermit crabs locate insects hiding under rocks or inside rotting wood. You should replicate the hermit crabs’ natural diet, which includes bugs.
Certain criteria apply to feeding insects to hermit crabs. You may find countless bugs in a tank, and it’s okay for hermit crabs to eat them. However, they’re usually too small to sustain a hermit crab long-term.
You can purchase pre-killed and frozen bugs. Hermit crabs aren’t hunters, preferring dead carcasses free from toxic pesticides.
Insects in a Hermit Crab Tank
Here are the most common bugs found in a hermit crab tank:
Booklice (Psocids) is the colloquial term for the Psocoptera or barkfly. They got their informal name through a taste for the paste that binds old books.
Booklice are tiny and often considered a pest in the home. They multiply frequently and enjoy the warmth and humidity of the hermit crabs’ enclosure.
The presence of booklice in an aquarium could be considered positive because they eat fungi and mold. Also, booklice aren’t aggressive insects.
The book Scorpion (Chelifer cancroides) is harmless to hermit crabs. This tiny bug is known as the pseudoscorpion because it has no tail.
Book scorpions are drawn to the warmth of hermit crabs’ enclosure. They’ll hide and hibernate in cold climates, concealing themselves in the substrate.
Book scorpions can be an invaluable addition to the hermit crabs’ habitat because they feed on small pests, such as mites, that may infest and irritate them.
Centipedes and Millipedes
You’ll likely invite centipedes (Scutigera coleoptrata) and millipedes (Diplopoda) into a tank with mossy plants. They’re so small they won’t harm hermit crabs and may make a light snack.
If left alone, centipedes and millipedes will rid an aquarium of decaying plant matter. Like many small bugs, this can provide a mutually beneficial relationship.
Hermit crabs eat fresh fruit but sometimes lose their appetite, which attracts fruit flies (Drosophila melanogaster). Don’t be surprised if you find flies in a tank.
Flies can be a nuisance because they hatch maggots that can crawl into the shells of hermit crabs. While hermit crabs eat maggots, they’re not a sanitary snack due to their habits.
Fungus gnats (sciarid flies) don’t attack hermit crabs. However, that doesn’t mean gnats should be left alone, as they’ll multiply quickly. As a result, each time you open the tank, they’ll escape and swarm.
While gnats eat rotting plant matter, other bugs do so without causing a problem. Apply sticky tape to the top of the tank to trap the gnats without placing any hermit crabs at risk.
There are thousands of species of mites, but not all are harmful. If you find mites (Acariformes) gathering around your hermit crabs’ mouthes, joints, or abdomens, they must be removed.
Some mites avoid hermit crabs, preferring food and substrate. This is less harmful but not beneficial, so a mite infestation should be removed by deep cleaning the tank.
Temporarily rehouse your hermit crab and empty the tank. Clean the tank from top to bottom, boil any decorations in ion water, and completely replace the substrate.
Spiders (arachnids) enjoy a hermit crab’s tank due to the warmth and hiding places.
Spiders, except venomous breeds, won’t harm hermit crabs. Usually, spiders and hermit crabs coexist. Spiders may prey on other small bugs in the enclosure, which can assist with population control.
The only thing to be wary of with spiders is their predilection for spinning webs because hermit crabs can become trapped and grow stressed.
Springtails (Collembola) are among the oldest insect species, dating back 400 million years. They’re tiny, reaching 1⁄8 of an inch. They’re common guests in a hermit crab’s enclosure as they like humidity.
Springtails clean a hermit crab’s tank, eating waste, leftover food, and decaying plant matter.
Woodlice (Oniscus asellus) may enter a tank through wooden logs, branches, and similar hiding places. The warm and humid environment enables woodlice to flourish.
Woodlice should be welcomed into a hermit crab’s tank. They won’t harm hermit crabs and can provide sustenance. More importantly, woodlice devour decaying plants.
Many owners of exotic pets invite woodlice into a tank. They’re nature’s cleaners, ridding a habitat of old, unwanted plant life. If you find woodlice in your enclosure, leave them be.
What Kind of Insects Can Hermit Crabs Eat?
Most insects, arachnids, and crustaceans prey upon each other, meaning the tank can become a tiny ecosystem.
You may wish to offer your hermit crabs other bugs to eat, but this comes down to preference. Hermit crabs don’t need insects to flourish. All the same, bugs and other invertebrates can provide dietary diversity.
So, you may purchase insects for feeding from exotic pet stores. Avoid feeding hermit crabs bugs from your yard as they may be coated in pesticides or carry diseases.
Do Hermit Crabs Eat Mealworms?
Mealworms (Tenebrio molitor) are the larval incarnation of the mealworm beetle.
Hermit crabs enjoy eating mealworms because they provide taste, protein, and calcium. Put some mealworms into a bowl, whole or chopped.
As with all insects, thawed mealworms can be fed to hermit crabs 1-2 times weekly.
Do Hermit Crabs Eat Crickets?
Hermit crabs will enjoy crunching through the tough exoskeleton of crickets (Grylloidea), but they must only be fed frozen (thawed) pre-killed crickets.
Crickets from a yard may have consumed pesticides or herbicides. In addition, crickets’ rapid, skittish movements may frighten hermit crabs.
Do Hermit Crabs Eat Earthworms?
Many hermit crabs enjoy eating earthworms (Lumbricus terrestris) because they’re juicy and meaty. A feeding frenzy will ensue if you offer a small bowl of earthworms to hermit crabs.
Don’t just dig up earthworms from the yard, as they may have crawled through fertilizer, pesticide, bacteria, fungi, or other pathogens. Again, buy earthworms from a pet store.
Earthworms may dig into the substrate, ruining any tunnels made by hermit crabs. Also, hermit crabs must compete for space under the substrate, causing avoidable distress.
Benefits of Feeding Insects to Hermit Crabs
Bugs can clean a habitat and keep it sanitary. They won’t do this single-handedly but certainly assist with cleanliness. Spot cleaning will become less troublesome with assistance from insects.
Insects and invertebrates provide protein while reminding hermit crabs of their natural environment. Perhaps most importantly, they’ll offer additional nourishment and dietary diversity.
Risks of Feeding Insects to Hermit Crabs
There should be no risk of feeding shop-bought, pre-killed insects to hermit crabs, as these bugs can’t fight back and will be tested for safety. The only real hazard is rotting, so uneaten bugs should be removed within 24 hours.
Live insects carry risk. Hermit crabs prefer not to hunt and subdue prey. Making hermit crabs work for a meal may cause physical harm or distress.
This can unbalance the ecosystem of the hermit crabs’ habitat. Larger bugs, like crickets, may prey on smaller insects. Also, larger insects may multiply and become the dominant species in the tank.
Hermit crabs can eat insects, and wild hermit crabs frequently do so. Insects aren’t a hermit crab’s first food choice, but they can supplement their basic nutritional requirements.