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how to treat mites on hermit crabs

How To Get Rid of Mites on Hermit Crabs

Any territory occupied by living creatures will attract mites.

Mites are particularly fond of hermit crab enclosures because the warm, dry, and dark conditions of the habitat of your hermit crabs are nirvana for mites.

If you have a mite infestation, bathe your hermit crabs in saltwater 2-3 times a day.

Rehome them in a clean enclosure and complete a root-and-branch deep clean of their aquarium. Never use an over-the-counter parasite killer because this will kill your hermit crabs.

Do Hermit Crabs Get Mites?

Many common household pets struggle with mites, and hermit crabs are no exception. Wild hermit crabs often welcome symbiotic relationships with other species. Mites, alas, are usually unwelcome visitors.

Hermit crabs are arguably likelier to attract mites than any other pet. A hermit crab habitat is warm and humid, which are ideal conditions for mites. They will gravitate to such surroundings.

As per the Journal of Experimental Marine Biology and Ecology, approximately 15 types of mites attach to hermit crabs. In captivity, the most common mites you will encounter are:

  • Psocoptera – better known as booklice, paperlice or barkflies
  • Dermatophagoides – aka dust mites
  • Acarus siro – aka grain mites
  • Oribatid – aka soil mites or moss mites
  • Liponyssoides sanuineus – aka house mouse mites
  • Demodex folliculorum – aka follicle mites
  • Sarcoptes scabiei hominis – aka itch or scabies mites
  • Tyrophagus putrescentiae – aka mold mites

Learning how to identify mites, as well as the risks of their presence and the impact they have on hermit crabs, is vital. Some mites are harmless. Others will make your hermit crabs unwell. It is always preferable to keep any trace of mites out of an aquarium.

What Causes Mites on Hermit Crabs?

Mites are all around us in the home. Oftentimes they are harmless, and we do not notice their presence. Mites love 4 things – warmth, humidity, darkness, and hiding places.

The enclosure that houses your hermit crabs offers these in abundance. Also, there will be a plentiful supply of uneaten food for the mites.

You may even bring mites into your hermit crab enclosure yourself, albeit unwittingly. Fresh food may have tiny mites crawling on it. Equally, external sources of wood, rocks, or shells may house mites. This is often how hermit crabs get mites.

Once mites have a foothold, they multiply quickly. A mite will only live for around 2 months. Mites lay up to 3 eggs per day, which hatch in short order. A small mite population can quickly become an infestation.

how to get mites off hermit crabs

Can Mites Kill Hermit Crabs?

Some mites are harmless to hermit crabs. Unfortunately, others can kill your pets. Mites that feed on hermit crabs can pass on bacterial diseases. Also, the stress due to the discomfort of mites can end a hermit crab’s life.

If you find mites in your hermit crab habitat, but not on the hermit crabs themselves, they will not be fatal. These arachnids should still be disposed of as you do not want them to become dominant.

Do My Hermit Crabs Have Mites?

Mites are not always easy to spot with the naked eye. All the same, you should inspect your hermit crabs for traces of mites. White mites on hermit crabs must be immediately removed. Use a magnifying glass, if necessary.

If you cannot rely on your eyesight, check for unusual behavior. Mites that attach to a hermit crab can cause discomfort. This physical distress will be reflected in the way your hermit crabs behave.

What Do Mites Look Like on Hermit Crabs?

If you have access to a magnifying glass or microscope, place a mite under it. You will notice the distinct body shape. They closely resemble ticks. Mites can vary in color but are typically white, brown, black, or red.

When inspecting a hermit crab for mites, pay particular attention to the following parts of the anatomy:

  • Legs
  • Abdomen
  • Antennae
  • Eye stalks

They are areas that mites are likeliest to cluster. You will notice the mites moving and crawling around. If you do happen to notice mobile specks on a hermit crab’s body, mites are almost certainly the culprits.

Effects of Mites on Hermit Crabs

Essentially, mites are an irritant to hermit crabs. They are unlikely to bite a hermit crab. They will cause constant itching and discomfort, though. This will make the hermit crabs stressed.

As discussed, mites on hermit crabs are not always easy to see. You may need to rely upon watching out for the effects of these parasites. Excessive bathing is a sign of mite infestation. The hermit crabs are trying to wash away their parasites.

Look out for signs of hyperactivity in your hermit crabs, especially during the day. They are trying to escape the mites. The opposite can also be true if the mites have passed on a bacterial infection that makes hermit crabs sick and lethargic.

Another common reaction to mites is the severance of limbs or eyestalks. Hermit crabs regenerate lost legs when molting. They may consider self-mutilation a temporary price worth paying. Alas, if hermit crabs lose too many limbs at once, they are unlikely to survive.

How to Treat Mites on Hermit Crabs

If you spot mites on your hermit crabs, you must never apply an anti-parasite treatment designed for other animals. Many pet stores will sell sprays that kill mites on the spot. While undeniably effective, these treatments will also kill hermit crabs.

Instead, treating mites in a hermit crab enclosure involves dedicated cleaning. Temporarily rehome your hermit crabs and bathe them until all unwelcome parasites are removed.

After this, you will need to complete a thorough deep clean of the habitat. This means removing everything and either washing, baking, or replacing it. You cannot cut corners in this process.


Naturally, the best way to keep mites out of a tank is to prevent them from getting in. This is not always possible. Mites are so omnipresent that they are sometimes unavoidable. Take these steps to minimize risk:

  • Spot clean a habitat daily and perform a deep clean every three months
  • Get an airtight lid to make access for mites difficult
  • Never leave strong-smelling, uneaten food to linger
  • Remove any moss or bacteria on sight
  • Thoroughly wash fresh food before feeding to hermit crabs
  • Boil any wood or shells in water before applying to a tank

Additional Insects

The enclosure of captive hermit crabs can become its own private ecosystem. If you introduce other, hermit crab-safe insects to a habitat, they may eat mites.

What’s more, these additional insects can serve other helpful purposes. Many will clean the enclosure by eating leftover food and waste. They even make a snack for your pets, if required. Hermit crabs sometimes eat bugs.

Do not just collect insects from your backyard and place them in a tank. Some may be more antagonistic than others or could have previously consumed insecticide.


If your hermit crabs are scheduled to molt, they will often speed up the process to rid themselves of mites. Mites attach themselves to the exoskeleton of hermit crabs. Molting removes this exoskeleton entirely, replacing it with a new, mite-free alternative.

Unfortunately, this is far from a permanent solution. The mites will continue to dwell within an enclosure. If still alive, the mites will reattach to the molted crab’s new exoskeleton once it emerges. You are not solving the problem, just kicking the can down the road.

Cleaning the Habitat

If you notice mites in an enclosure, it must be thoroughly cleaned. The mites attached to their pet are a small number of the total parasites. Many more will be waiting in the wings to take their place.

With this in mind, you must have at least two aquariums for your hermit crabs. Deep cleaning a hermit tank takes at least a day – usually two or three. Your pets will need somewhere to dwell in between.

Settle your hermit crabs into a temporary home, then clean their primary habitat. Remove everything from the tank and get to work step-by-step.

Floors and Ceilings

Invest in a small aquarium vacuum for your enclosure and apply this to the floor and walls. Do this before you start cleaning, as these vacuums are most effective on dry surfaces. They will suck up any mites that are still hiding within the now-spartan environment.

Fill a bucket or jug with warm water mixed with white vinegar. Take a clean sponge and thoroughly wipe down every surface in the tank. Do not use bleach. As impactful as it may be, remnants will be toxic for hermit crabs upon their return.

Once you have wiped the tank’s walls and floor, leave it outside to dry in the sun. You could use a hairdryer first if that is your preference. The tank will not be ready for rehabilitation until it has air-dried, though. The UV rays of the sun will kill any lingering mites.


Before your tank is dry, you need to decide what to do with the substrate. There will almost certainly be mites within this substrate. If you use soil instead of sand, this is even likelier.

Arguably the safest option is to throw away the substrate and replace it. If you are unwilling or unable to do so, you need to sanitize the substrate before recycling it.

To do this, bake the substrate in the oven. Heat it for around thirty minutes at a temperature of 300 degrees Fahrenheit. If you have any wood in the enclosure, bake this at the same time. Let the substrate and wood cool before restoring it to the aquarium.

Decorations and Spare Shells

Consider any decorations in your hermit crab enclosure. This could include food dishes, swimming pools, climbing toys, and rocks. If you keep spare shells in the enclosure, these also need to be sanitized.

To achieve this, boil up a pot of water and place the accessories within. Ensure that no hermit crabs are hiding within shells first.

Once these items have been boiled for around twenty minutes, you should remove them and leave them to cool. When using sponges in your hermit crab enclosure, microwave these rather than boiling them.

Bathing the Hermit Crab

If you have a bona fide mite infestation, bathing is essential for the hermit crabs. This takes two forms. The hermit crabs will opt to submerge in saltwater themselves. You can also apply a little spot cleaning. Eventually, you’ll need to offer a full bath.


Initially, hermit crabs struggling with mite infestations will bathe themselves in saltwater. This will go some way to clearing up the problem. It’s advisable to let hermit crabs indulge in this behavior.

Place multiple bathing pools in the enclosure for at least a day. Consider warming the water slightly, but not enough to risk burns.

It’s the salt in the water that is essential here. As per African Zoology, hermit crabs can flourish in water with higher levels of salinity than they are used to. This must be marine salt as table salt contains iodine, which is toxic to hermit crabs.

can mites kill hermit crabs?

External Bathing

Fill a bowl with room temperature water and a little marine salt. This water must be wholly dechlorinated. It’s safest to get in bottled water for this task. Even a purifier may not clear all traces of chlorine in the volume of water required for this practice.

Gently place your hermit crabs in this water. Leave it in the water for around ten minutes. This will be long enough to kill any mites without leaving the crabs at risk of drowning. Turn your hermit crabs upside down to clear air bubbles, then drain any water from the shell.

Once this is done, use a soft paper towel to dab your hermit crabs dry. They are likely to be grumpy with you at this stage, so consider wearing gloves. You may be pinched. Repeat this process at least twice, ideally more, before returning crabs to a clean habitat.

Can Hermit Crab Mites Spread to Humans?

Most crabs that frequent hermit crab enclosures will not be interested in humans. These mites are tiny. As a result, there is no record of zoonotic diseases spreading from hermit crabs to humans through mites.

All the same, it remains avoidable to be safe. Wear gloves during cleaning and wash all clothing immediately afterward. Just because hermit crab mites will not bite humans, they may still attach themselves to skin or garments.

This will not be harmful but will become irritating. As mentioned, mites multiply at a rate of knots. If you’re not careful, your home will become a breeding ground. This will lead to an expensive and inconvenient fumigation process.

If you spot mites on your hermit crabs, take action at once. They will need to be bathed and rehomed while you clean the habitat.