are painted shells safe for hermit crabs?

Are Painted Shells Bad for Hermit Crabs?

Last Updated on September 30, 2023 by Joanne Harper

Gift shops on the beach sell hermit crabs in brightly painted shells to appeal to young children.

Never buy decorated shells or paint the shells of hermit crabs. Even if the paint no longer emits Volatile Organic Compounds (VOCs), it can flake off and is toxic if ingested.

Painted shells can also trap hermit crabs inside. If a hermit crab enters the shell before the paint is dry, it’s likely to become glued to the exoskeleton, meaning it can’t escape and will perish.

Do Hermit Crabs Prefer Plain or Decorated Shells?

Hermit crabs won’t choose a shell because it’s decorated. They have a limited understanding of different colors based on sight. This sense isn’t sufficiently evolved to result in aesthetic preferences.

According to the Journal of Experimental Marine Biology and Ecology, size and volume matter most to hermit crabs when selecting a shell.

The shell must be light enough to carry on its back and strong enough to protect it from harm.

Behavioral Ecology and Sociobiology discuss how the condition of a shell is critical. Hermit crabs want an undamaged shell that can withstand the sun and a predator’s attention.

Different hermit crabs need various shell openings, so they come in one of two styles:

  • The d-shaped opening is popular with the Coenobita compressus (Ecuadorian hermit crab.)
  • Round opening, which most other hermit crabs prefer.

These openings are considered small, medium, or large. As a rule of thumb, the opening should be slightly bigger than a hermit crab’s large cheliped.

Can You Decorate A Hermit Crab Shell?

As hermit crabs are indifferent to decorated shells, there’s no need to go to the effort of making over the vessel. Part of the aesthetic appeal of hermit crabs is the natural beauty of the shells they choose.

You may think there’s no harm in applying small decorations to a hermit crab for fun, such as gluing eyes or stickers. Even the slightest addition of adjustment to a shell can change its weight, leaving a hermit crab off-balance and disoriented.

Hermit crabs will never encounter a decorated shell in the wild, so forcing them into handling while you decorate their shell will cause stress that can be avoided.

are painted shells toxic to hermit crabs?

Is it Safe To Paint Hermit Crab Shells?

If you want to make enhancements, never apply paint to a shell because this is dangerous.

Are Painted Shells Toxic to Hermit Crabs?

The main concern is the fumes released by paint. The paint releases fumes with heavy metals that restrict breathing—painting a shell risks condemning a hermit crab to a slow death by suffocation. 

Your hermit crabs won’t be safe, even if you use fume-free paint. The humidity in a tank and a preference to soak in water regularly will cause paint to flake.

These paint flakes will end up floating in drinking and bathing water.

Can Hermit Crabs Get Stuck in Painted Shells?

Another danger of painted shells is that hermit crabs can get stuck within.

Vendors that sell hermit crabs in painted shells may not wait for the paint to fully dry and cure, which can lead to the hermit crab’s exoskeleton becoming ‘glued’ to the shell’s interior.

Hermit crabs must molt multiple times in their first year of life and around every 18 months after this.

Missing a molt stunts a hermit crab’s growth and prevents the regrowth of lost limbs. Your hermit crab may need to wait several years to become whole again.

If a hermit crab can’t leave of its free will, regularly bathe it in saline water. Eventually, this will loosen the shell’s grip and help your hermit crab wriggle free.

Make these dips short and frequent, changing the water each time to remove flaking paint.

Why Do People Paint Hermit Crab Shells?

People paint shells due to a lack of understanding of the dangers or disregard.

Beachfront gift shop vendors paint and decorate hermit crab shells as a sales tactic, making the hermit crabs more eye-catching when people pass by.

Many erroneously believe that hermit crabs are short-lived and disposable pets, so they purchase them for children. A painted shell is likely to be even more appealing.

A young child will rarely base their decision to adopt a hermit crab on its health and demeanor. Instead, they’ll be drawn to a shell painted to resemble a ladybug or feature their favorite superhero’s logo.

How to Get a Hermit Crab Out of a Painted Shell

Never attempt to pull a hermit crab out of its shell, as this will be mistaken for an act of aggression. Instead, tempt a hermit crab out of a shell of its own accord.

The first step to this is providing an alternative that the hermit crab will consider an upgrade. This could be a larger shell or one in better condition that offers superior protection.

Leave this shell in plain view of the hermit crab and attract attention with a sweet treat. When the hermit crab emerges to eat, it’ll decide whether it is interested in changing shells.

Place the hermit crab in a temporary isolation tank while it changes shells. This will prevent other hermit crabs in your colony from expressing an interest in the new shell and starting a conflict or attempting to claim the vacated painted shell, which must be thrown away.

hermit crabs forced into painted shells

Where to Find Unpainted Shells

Ensure you have a selection of undecorated alternatives for hermit crabs. You can search for these if you live near a beach or order shells designed for hermit crab use online.


Wild hermit crabs will search for new shells in their beach habitat.

You can do the same, bringing these shells into your pets’ habitat at home. Always look for a selection of shells, so hermit crabs can choose when to change vessels.

Most hermit crabs prefer a shell that has been found on the beach. As per Ecology and Evolution, hermit crabs are drawn to the scent of a dying conspecific, aware that a new shell will soon be available.

The concern with finding shells on the beach is that they may already be occupied. If a hermit crab feels threatened, it may hide within its shell, staying out of sight.

Don’t shake a shell to check if it has been claimed. Follow these steps:

  1. Stretch the skin of your palm tightly.
  2. Place the shell as though picking up a pet hermit crab in your hand.
  3. Wait a few seconds to see if a curious hermit crab emerges.
  4. If not, blow gently into the shell.

If there’s still no response, there is a good chance the shell is vacant.

Order Online

An aquatic pet store may sell a range of shells. A reputable online vendor will also have a range of shapes and sizes, often in one package. Shells are often sold by the bag, costing more than $5 – $10.

Painted shells are cruel and unnecessary for hermit crabs. Always offer your hermit crabs a choice of plain, natural shells in good condition to avoid health hazards.