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Can Hermit Crab Mites Spread to Humans? (And Are They Harmful?)

Can Hermit Crab Mites Spread to Humans? (And Are They Harmful?)
The purpose of this blog is to share general information and is written to the author's best knowledge. It is not intended to be used in place of veterinary advice. For health concerns, please seek proper veterinary care. In addition, as an Amazon Associate I earn from qualifying purchases.

Hermit crabs, like most other creatures, attract mites. These tiny, almost microscopic arachnids are attracted to your hermit crab’s food and bedding.

As a hermit crab owner, you know that you have to keep the crabs clean of parasites. But can hermit crab mites spread to humans?

Hermit crab mites can spread to humans by attaching themselves to your skin or clothes. These mites are too tiny to bite humans and thus cannot spread diseases to us. However, hermit crab mites can harm your hermit crab. They multiply rapidly, so you need to clean your hermit crab’s tank immediately.

Just as a parasite like a tick or a flea will irritate a dog and make it miserable, so will mites irritate hermit crabs. It would help if you were alert to the presence of mites on your hermit crabs so that you can get rid of them immediately.

Fortunately, most mites are not dangerous to humans, but they can spread quickly and cause an infestation.

Are Hermit Crab Mites Harmful To Humans?

Hermit crab mites are far too small to be interested in humans and larger animals and cannot bite us, so they cannot spread diseases.

The mite that is dangerous to humans is the human itch mite which causes scabies, an unpleasant disease that manifests as an itchy, scaly rash and blisters. Hermit crabs do not attract the human itch mite.

Hermit crab mites can spread to humans in that they can attach themselves to your skin or clothes. These mites are only harmful in the sense that they could infest your food, as grain mites love to live in dry food staples in your pantry.

What Kinds of Mites Do Hermit Crabs Attract?

Hermit crabs attract several different kinds of mites and bugs, most of which are harmless. Unfortunately, it is pretty difficult to distinguish between the different types of mites, so most owners will do a thorough clean if they see any mites at all.

These are the most common mites you will find in your hermit crabs’ environment.

Booklice

Booklice

Mites known as booklice live in your home and are helpful as they feed on mold and fungi. They are harmless to hermit crabs.

Food Mites

Food, wood, or grain mites are only interested in sharing your crab’s bedding and food in the crabitat and are also completely harmless. In fact, they will help break down waste products in the crabs’ environment.

These are the mites you are most likely to see as these fat white critters tend to swarm around the crabs’ food dishes, drown in their water, and lurk in their substrate.

Unfortunately, they are very hard to get rid of as they tend to live in your home and will return to the crabitat, attracted by the warmth, humidity, and food.

Soil Or Moss Mites

These orabatids or tiny, dark mites are also harmless. You hardly ever notice them because they bury themselves in the substrate.

They feed on decaying plant material, so they are often present in the fiber you buy as a substrate – this is why many hermit crab fans prefer sand in their crab tanks.

Mesostigmata

These long-legged mites are predatory and consume other mites. Some hermit crab owners choose to include them in their crabitats as they keep down the population of other mites and leave the hermit crabs alone.

Antenna Mites

You may see white mites living on the crabs’ antennae. Some hermie owners suggest that these are mites simply hitching a ride on the crabs and not harming them, but they can irritate the crabs that try to scrape them off themselves.

However, repeatedly bathing your crabs to remove the mites is equally stressful. Monitor your crabs to see whether the mites are bothering them.

Hermit Crab Mites

Unfortunately, some kinds of mites can end up living on the crab and its shell, which can stress and irritate crabs. There are also highly unpleasant predatory mites that will live on crabs’ eyes and in their joints – like ticks on a dog – and even make them sick and kill them.

These mites spread from crab to crab; therefore, they need to be destroyed as soon as possible or else they will infest all the crabs in the crabitat.

How Do Hermit Crab Mites Spread?

Grain Mites

It is essential to know that hermit crabs are not the source of mites, except for hermit crab mites which can only be introduced via a new hermit crab.

For example, grain mites usually come into your home via food and will then spread to your hermit crabs. Mites can also spread to hermit crabs through sand, wood, rocks, shells, or the substrate you purchase for their tanks. Mites can even spread via human beings.

Although mites are tiny, they breed quickly so that a few mites can lead to an enormous infestation. You should therefore get rid of mites as soon as you see them.

How Do You Know If Your Hermit Crabs Have Mites?

Some mites you can see with the naked eye, such as the white food mites you may see on your hermit crab’s shell. You also get black, red, and brown mites, which will appear as tiny moving specks on the hermit crab.

Mites most often cluster around the crab’s legs, abdomen, antennae, and eyestalks.

However, many mites are too tiny to be visible, so you need to monitor your hermit crab’s wellbeing and behavior to see whether it has mites.

Signs of mites in hermit crabs are irritation and itching, which will make the hermit crabs hyperactive. Hermit crabs will also bathe excessively to wash away the mites. It would help if you always supplied your hermies with a bathing dish of salt water for them to soak.

Sometimes hermit crabs will speed up their molting cycle to get rid of mites. Molting does ease the crab’s irritation, but hermit crabs are very vulnerable while they are molting. Unfortunately, the mites will remain in the tank and reattach themselves to the hermit crab again unless you clean out the tank.

In extreme cases, hermit crabs will self-mutilate, removing their own limbs and eye-stalks to get rid of the mites. The appendages will regenerate, but the hermit crab can die if too many limbs are lost at once.

If the hermit crab has caught a disease from the mites, it will be lethargic and may also die.

Getting Rid Of Hermit Crab Mites

If your hermit crabs have a mite infestation, you need to take action immediately to avoid the mites damaging your hermit crabs and infesting the rest of your home. You will need to clean both the hermit crabs and their tank to kill the mites and any eggs.

Take Personal Precautions

Putting on Cleaning Gloves
  • Before tackling the hermit crab tank or washing your hermit crabs, make sure to wear gloves.
  • After cleaning the tank, remove all of your clothes and wash them immediately.

Keep Your Hermit Crabs Clean

If you notice that your hermit crabs have mites, you will need to let them bathe or bathe them in salt water at least two or three times a day – see what your hermies can tolerate, as you don’t want to stress them further.

  • Hermit crabs will bathe themselves in salt water to get rid of mites. Provide them with a pool or dish of warm salt water for bathing and a plate of fresh water for rinsing.
  • Never use iodized salt – iodine is toxic to hermit crabs.
  • Always use dechlorinated water, preferably bottled rather than just purified.
  • You can also bathe your hermit crabs by placing them in a dish of warm, salted water for about 10 minutes – each crab in a separate bowl. Turn the crab upside down to remove air bubbles, then turn it the right way round to drain water and mites from the shell. (They will often turn themselves over, but you may need to help.) Rinse the crabs in ordinary dechlorinated water by swishing them gently back and forth to neutralize the salt water. Use a soft paper towel to dry them.
  • Check that mites are coming off in the water.
  • Continue with the bathing process every day until you see no more evidence of mites. The incubation period for mite eggs is three days, so you will need to continue the process for at least that long to ensure all mites and eggs are gone.
  • Vets can prescribe a specific anti-mite medication for hermit crabs, but take care that it is precisely for crabs as the treatment for reptile mites is toxic to hermit crabs.

Move The Hermit Crabs

You will need to move your hermit crabs to a clean enclosure at the first sign of mites. It is therefore vital to have more than one tank available to house the hermit crabs. It can take a few days to clean a tank and everything in it thoroughly.

Keep the clean enclosure completely sterile, or you will risk returning the hermies to their home with mites and start the process all over again.

  • Use unbleached paper towels as the substrate.
  • Include some crumpled, damp towels for the crabs to hide behind and to help with humidity.
  • Provide a dish of salt water for the crabs to bathe in. Remember to keep it shallow and to include pebbles for the crabs to climb on so that they don’t drown.
  • Include a dish of fresh water for the crabs to alternate.
  • Use fresh food dishes for every feed and replace the food daily.
  • Use something simple to clean, like a plastic tub with a “door,” as a hide.
  • Provide clean, sterilized shells.

Clean this sterile enclosure thoroughly each time you take the crabs out to bathe them.

Clean The Hermit Crab Tank

White Spotted Hermit Crab on Sand in Aquarium

Once the hermit crabs are safe, thoroughly clean their tank. However, you cannot use an over-the-counter parasite cleaner, as this is fatal to hermit crabs.

Floors And Ceiling

  • Mites can lurk on the floors and roof of the tank and get stuck in the tiny corners. Use a small aquarium vacuum cleaner on the dry surfaces to get rid of any lurking mites.
  • Wash out or rinse out the tank thoroughly with water, focusing on the corners where mites hide.
  • Wipe down all the surfaces with warm water and vinegar. Do not use bleach, as this will kill both the mites and your hermit crabs.
  • Put the hermies’ tank in the sun to dry and allow the UV rays to sterilize the tank, killing any remaining mites.

Substrate

  • There will definitely be mites in the substrate, whether you are using soil, sand, or coconut husk chips. The best option with substrate is to throw it out and replace it. Bag up the infested substrate and throw it in an outside garbage bag to avoid an infestation in your home.
  • However, if you want to sterilize your substrate thoroughly, bake it in the oven at 300 ⁰F (120⁰C). Allow it to cool completely before reusing.

Accessories

  • If possible, get rid of as many accessories and toys as you can: these will also be infested with mites.
  • Sponges, which are great for keeping the crabitat humid, are unfortunately mite-attractors. Replace any sponges regularly and between times; keep them clean by microwaving them.
  • Any accessories, such as food bowls, swimming dishes, shells, rocks, toys, plastic castles, etc., will also need to be thoroughly cleaned by being immersed in boiling water for 20 minutes. Allow these to cool completely before reusing.
  • Check carefully that no crabs are hiding inside these items before washing them.

Purchase Predator Mites

If you’re not squeamish about bugs, then you may want to introduce predator mites into the crabitat. You can order these mites online or purchase them from garden centers, where they are used to combat bugs in greenhouses.

Predatory mites are helpful in that they will eat the other mites, larvae, and eggs but ignore the hermit crabs completely. They live on protein, and once the other mites are all eaten, they will stop reproducing and die off as well.

Check Your Pantry For Mites

If there is a mite infestation in your crabitat, the source may be the dry food in your pantry.

  • Check all dry foods that have been on the shelf a while, such as flour, pancake mix, rice, or noodles. You will see evidence of mites if they are there – they leave a rough, claggy trail.
  • Throw away all food that is infested with food mites.
  • Clean out the pantry shelves with a good cleaner or even vinegar and water.

Preventing Hermit Crab Mites

The best way to avoid hermit crab mites in your home is to prevent them from spreading in the first place.

  • Check your hermit crab for mites every day.
  • Keep the hermit crabs’ habitat clean by doing basic cleaning every day (e.g., cleaning away any moss or algae; removing crab droppings and old food) and a thorough cleaning once a week.
  • Replace all water in the tank daily.
  • Ensure that the tank has an airtight lid or tape it closed.
  • Wash all food before feeding the hermit crabs.
  • Never leave uneaten food in the hermies’ tank, as mites are attracted to strong-smelling food like shrimp or plankton. They will burrow right into the old food.
  • Boil all wood and shells before adding them to the habitat.
  • Avoid keeping live plants near the hermit crab enclosure as mites can move from plants to the hermit crabs.

Final Thoughts

Although hermit crabs are susceptible to mites, hermit crab mites are unlikely to harm humans or other animals in your home. However, hermit crab mites can harm your hermies.

To avoid these parasites, keep your hermit crab’s environment clean and take immediate action if you see any mites in or around your hermit crab.