Can Hermit Crabs Live in Freshwater? Why Land Hermit Crabs Need a Dry Terrarium

Q: If land hermit crabs can't live in water, why do they need water dishes at all?

Because drinking, hydration, and the saltwater-related needs covered in our hermit crab saltwater guide all require access to water, just not living in it. Think of it less like 'does this animal live in water' and more like 'does this animal need a water source available, the way a dry-land animal still needs a water bowl.' Land hermit crabs need both a fresh water dish and a saltwater dish, both designed for easy entry and exit — and separately, they need high humidity in the air of the terrarium itself, which is yet another distinct consideration related to their retained gills, but still not the same as 'living in water.'

By Hektor Jorgo Published January 20, 2026 Updated June 14, 2026 3 min read

A land hermit crab on dry sand substrate near a shallow water dish in a terrarium

Quick Facts

Animal in Question: Land hermit crabs (genus Coenobita) — terrestrial pets, not aquatic animals
Short Answer: No — land hermit crabs would drown if kept fully submerged in water, fresh or salt
What Fresh Water Is For: Drinking and hydration via a shallow dish, not a living environment
Drowning Risk: A deep or steep-sided water dish without an easy exit can drown even a land hermit crab that 'just' fell in
Correct Setup: Dry/humid substrate as the main living area, with shallow fresh water and saltwater dishes the crab can enter and exit easily
Different From Aquatic Hermit Crabs: Some hermit crab species are fully aquatic and marine — a separate category from land hermit crabs entirely
Humidity vs. Water: Land hermit crabs need high humidity in the air, which is different from needing to be in water
Related Question: Land hermit crabs DO need access to saltwater too — but as a dish to enter, not a living environment

"Can hermit crabs live in freshwater?" is a question that makes a lot of sense for a fish — and almost no sense for the land hermit crabs most people keep as pets, once you understand what their setup actually looks like.

Short Answer

No — land hermit crabs (genus Coenobita) cannot live submerged in water, fresh or salt, and would drown if kept that way. Their primary living environment is dry-to-humid substrate, not water. That said, they do need access to water dishes — both fresh water and saltwater, covered in our hermit crab saltwater guide — for drinking, soaking, and molting-related needs. The distinction that matters is "needs a water source available" vs. "lives in water" — land hermit crabs need the former, not the latter.

A Terrarium, Not a Tank

A land hermit crab's home is fundamentally a terrarium: substrate (sand, coconut fiber, or similar) deep enough for burrowing, high humidity in the air, hiding spots, and — critically — shallow water dishes rather than a body of water as the main feature. This is a completely different setup model from an aquarium, even though "hermit crab" might bring aquatic associations to mind.

Why Water Dishes Can Still Be a Drowning Hazard

Here's the part that can seem contradictory: land hermit crabs need water dishes but can drown in them. The resolution is that the risk isn't water itself — it's water a crab can't easily exit. A water dish that's:

Too deep relative to the crab's size
Steep-sided with no easy foothold

...can trap and drown a crab that climbs or falls in, even though the same animal handles a shallow, easy-to-exit dish without any issue. Practical fixes include keeping dishes shallow, adding gently sloping sides, or placing small rocks or a sponge in the dish that give a crab something to climb on to get out.

Two Different Water Needs, Neither of Which Is "Living in Water"

Land hermit crabs have two separate water-related needs, and it's worth being clear that neither one means "living in water":

Fresh water — for drinking and general hydration
Saltwater (marine salt mix, not table salt) — for molting and other physiological needs, covered in detail in our hermit crab saltwater guide

On top of both of these, land hermit crabs need high humidity in the air of the terrarium — yet another distinct requirement related to their gills, and again, not the same thing as "living in water." Three separate considerations, all related to moisture in some sense, none of which involve the crab actually living submerged.

What "Hermit Crabs in Water" Usually Does Mean

If you're picturing a hermit crab that genuinely lives in water, you're probably thinking of a different group entirely — the small, fully aquatic marine hermit crab species (blue leg, scarlet/red reef, and similar) covered in our reef-safe hermit crab guide, which live submerged in reef tanks as cleanup crew. These are genuinely different animals from land hermit crabs, with genuinely different care models — one lives in a terrarium with water dishes, the other lives in a saltwater tank, full stop. "Hermit crab" as a name covers both, but the care information for one doesn't transfer to the other.

Quick Reference

Land hermit crabs (Coenobita species) cannot live submerged in water — they would drown
Their living environment is dry-to-humid substrate (sand, coconut fiber), not water
They still need shallow, easy-to-exit fresh water and saltwater dishes
Deep or steep-sided water dishes are a drowning hazard even though water dishes are needed
High humidity in the terrarium air is a separate requirement from water dishes
Fully aquatic marine hermit crabs (reef tank cleanup crew) are a completely different group
"Needs water access" and "lives in water" are different things for land hermit crabs

Frequently Asked Questions

Can a land hermit crab live in a tank of water?

No — land hermit crabs (genus Coenobita) are terrestrial animals and would drown if kept fully submerged, whether the water is fresh or salt. This might seem counterintuitive given that land hermit crabs also need saltwater as part of their setup — but needing access to a water dish and living submerged in water are very different things. A land hermit crab's primary living environment is dry-to-humid substrate (sand, coconut fiber, or similar), with shallow water dishes available for drinking, soaking, and the saltwater-related needs covered in our hermit crab saltwater guide — not a tank filled with water as the main habitat.

What's the actual drowning risk with water dishes in a hermit crab terrarium?

The risk isn't really 'too much water in the terrarium' — it's specific water dishes that are too deep or too steep-sided for a crab to easily climb out of. A land hermit crab that falls into or climbs into a water dish it can't easily exit can drown, even though the same crab is perfectly fine using a shallow, easy-to-exit dish for drinking or soaking. This is why water dish design matters: shallow depth, gentle sloping sides, or items like small rocks/sponges that give the crab something to climb on are commonly recommended, rather than deep, smooth-sided containers. The goal is access to water without creating a hazard.

If land hermit crabs can't live in water, why do they need water dishes at all?

Because drinking, hydration, and the saltwater-related needs covered in our hermit crab saltwater guide all require access to water, just not living in it. Think of it less like 'does this animal live in water' and more like 'does this animal need a water source available, the way a dry-land animal still needs a water bowl.' Land hermit crabs need both a fresh water dish and a saltwater dish, both designed for easy entry and exit — and separately, they need high humidity in the air of the terrarium itself, which is yet another distinct consideration related to their retained gills, but still not the same as 'living in water.'

Are there hermit crabs that DO live fully in water?

Yes, but they're a completely different group from the land hermit crabs discussed here. Some hermit crab species are fully aquatic and marine, living submerged — these include the small 'dwarf' hermit crab species (blue leg, scarlet/red reef, and similar) covered in our reef-safe hermit crab guide, which are kept in reef tanks as cleanup crew and spend their entire lives in saltwater. If 'can hermit crabs live in freshwater' is really asking about that category of fully aquatic hermit crab, the more relevant question is whether a marine species could tolerate freshwater — a salinity-tolerance question covered more generally (for crabs, not hermit crabs specifically) in our saltwater crabs in freshwater guide. But for the terrestrial pet hermit crabs most people are asking about, the answer to 'can they live in water' is simply no, regardless of salinity.

Sources & Further Reading

About the Author: Hektor Jorgo

Co-Founder & Marine Biologist

Hektor is a co-founder of Sea Life Planet and has kept reef and freshwater aquariums for over 15 years. He holds a background in marine biology and focuses on species care accuracy, water chemistry, and tank husbandry.