How Do Hermit Crabs Drink?
If you’ve just brought home a land hermit crab, one of the first questions you might have is:
How do hermit crabs actually drink water?
You probably won’t see them “drink” the way a dog or cat does… which can make it confusing (and a little worrying). Let’s break it down in a simple, clear way so you know exactly what your crab needs to stay healthy.
By Fred (and Chris) | Updated 04/09/26
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Do Land Hermit Crabs Drink Water?
Yes, they absolutely do.
Land hermit crabs need water to survive, but they don’t drink in obvious ways. Instead of lapping water, they absorb and move moisture through their mouthparts and specialized structures near their gills.
They also store water inside their shells, which helps them stay hydrated and maintain the humidity they need to breathe.
Where Is a Hermit Crab’s Mouth?
A hermit crab’s mouth is not easy to see.
It’s located underneath their body, between their front claws, surrounded by small feeding appendages called maxillipeds. These tiny appendages help move food and water into their mouth.
So if you’re watching your crab from above, you probably won’t notice them drinking at all.
How Do Hermit Crabs Drink From a Water Dish?
This is the part most new owners are curious about.
Hermit crabs don’t scoop water up and sip it. Instead, they:
- Walk into or near the water dish
- Use their small mouthparts to pull in water
- Absorb moisture through their gills and body
- Sometimes fill their shell with water for storage
You may occasionally see your crab sitting in the water bowl—that’s normal. They’re not just “hanging out”… they’re hydrating and regulating moisture.
Do Hermit Crabs Need Both Fresh and Salt Water?
Yes! And this is very important!
Land hermit crabs need access to both types of water at all times:
Fresh Water
- Used for drinking and hydration
- Helps regulate internal balance
Salt Water
- Mimics their natural coastal environment
- Supports proper biological functions
- Helps maintain shell water reserves
⚠️ Important:
Salt water must be made using a marine salt mix (like Instant Ocean), not table salt.
Can Hermit Crabs Drink Tap Water?
No—you should avoid tap water.
Most tap water contains:
- Chlorine
- Chloramines
- Heavy metals
These can be harmful or even deadly to hermit crabs over time.
What to Use Instead:
- Dechlorinated water (treated with a water conditioner)
- Bottled spring water
- Reverse osmosis (RO) water (re-mineralized if needed)
Clean, safe water is one of the simplest ways to prevent health problems.
What Kind of Water Dishes Do They Need?
To properly support drinking and hydration:
- Provide two separate dishes (fresh + salt)
- Make them deep enough for your crab to submerge
- Include easy ways to climb in and out (rocks, ramps, shells)
- Keep them clean and refilled daily
Hermit crabs often like to fully enter the water—this is normal and healthy.
Why Water Matters More Than You Think
Water isn’t just about drinking for hermit crabs.
It plays a role in:
- Breathing (they use modified gills that need moisture)
- Molting (critical for survival and growth)
- Maintaining humidity inside their shell
- Overall stress and health
Without proper water access, hermit crabs can quickly become dehydrated even in a humid tank.
Final Thoughts
Even though you may never see your hermit crab take a sip, they are constantly interacting with water in ways that keep them alive and thriving.
If you remember just a few key things, make it these:
- Provide both fresh and salt water
- Never use untreated tap water
- Make dishes safe and accessible
- Expect subtle, not obvious, drinking behavior
Getting this right early on makes a huge difference in your hermit crab’s health and lifespan.