How Long Can Hermit Crabs Live Without Food?

Hermit crabs are fascinating pets, full of quirks that often surprise new owners. One of the most common questions is: how long can hermit crabs live without food?

The short answer: Hermit crabs can survive 1-2 weeks without food in ideal conditions, but it is never safe or healthy to let them go hungry. In captivity, they should always have access to fresh food and water.

In this guide, we’ll explore how hermit crabs eat, how long they can really go without food, why molting is an exception, and how to set up a feeding routine that keeps them thriving.

Why This Question Matters

Unlike cats or dogs, hermit crabs don’t have an obvious daily eating schedule. Some days, they eat a lot; other days, they barely touch their food. This leads many owners to wonder if they can “skip meals” safely.

Understanding their survival limits helps you:

• Prevent accidental starvation during vacations
• Recognize natural fasting periods (like molting)
• Set up a safe and stress-free feeding routine

On hermit crab forums like Hermit Crab Association, keepers often share stories of crabs fasting for days. Knowing what’s normal (like molting) versus dangerous (lack of food/water) helps prevent mistakes.

How Do Hermit Crabs Eat?

To understand how long they can survive without food, it helps to know how hermit crabs eat and process nutrients.

• Mouthparts: Hermit crabs don’t chew like mammals. They use small pincers to tear food into tiny pieces.
• Scavenger diet: In the wild, they eat algae, rotting plants, decaying animals, plankton, fruits, and even wood.
• Slow metabolism: They process food more slowly than mammals, which partly explains why they can last longer without meals.
• Water connection: Food and water go hand in hand. They moisten food with water before eating, which means water access is just as critical as food.

How Long Can Hermit Crabs Live Without Food?

The survival time depends on environmental conditions and whether the crab is wild or captive.

• Wild hermit crabs: Adapted to unpredictable food sources, they can survive up to 1-2 weeks without food, sometimes longer if water is available.
• Captive hermit crabs: They rely entirely on their owner. If deprived, they may weaken within days and die within 1-2 weeks, especially if water is also lacking.

👉 On Reddit’s hermit crab community, many owners report that while their crabs survived short fasting spells, it stressed them and reduced activity.

How Long Can Hermit Crabs Live Without Food and Water?

Food scarcity is tough, but water scarcity is fatal. Hermit crabs breathe with modified gills that must stay moist. Without water:

• They may survive only 3-7 days, even if food is present.
• Dry gills mean they literally suffocate.
• Molting without water is impossible.

💡 Always provide two dishes: one of dechlorinated freshwater and one of saltwater (made with marine aquarium salt, not table salt).

Molting: The Natural Exception to Eating

Hermit crabs stop eating for days or weeks when preparing to molt. This can worry new owners, but it’s completely natural.

What happens during molting?

• Crabs bury themselves in the substrate.
• They stop eating surface food.
• They live off stored fat and water.
• After shedding their exoskeleton, they eat the old shell for extra nutrients.

Depending on size, molting can last 2 weeks (small crabs) to 8+ weeks (large crabs).

👉 If your hermit crab is buried and not eating, don’t dig them up. It’s likely molting, not starvation.

Why Do Hermit Crabs Sometimes Refuse to Eat?

If your hermit crab hasn’t touched food for a few days, several factors could be at play:

1. Molting preparation – The most common reason.
2. Stress from a new environment – Crabs may fast for days after being introduced to a new tank.
3. Poor tank conditions – Incorrect humidity (below 70%) or temperature (below 72°F) suppress appetite.
4. Food preferences – Hermit crabs are picky. They may ignore certain foods for days.
5. Illness or dehydration – Lack of clean water can also reduce eating.

👉 Always check tank conditions first. If all is well, your crab is probably fine.

Emergency Feeding: What to Do If You Can’t Feed Them

Life happens-you might travel, forget to restock, or lose track of feeding. Here’s how to handle it:

• Short absence (1-2 days): Crabs will be fine, but leave food in the tank just in case.
• Medium absence (3-5 days): Provide large portions of stable foods like dried seaweed, pellet food, or dried shrimp.
• Long absence (1-2 weeks): Ask a friend to refill water and food. Hermit crabs cannot be left this long unattended.

Foods that last longer in the tank:

• Dried seaweed
• Unsalted nuts
• Commercial hermit crab pellets
• Coconut flakes
• Cuttlebone for calcium

Hermit Crab Feeding Schedule

To prevent your pets from ever reaching their survival limit, here’s a simple feeding routine.

Timeframe	What to Do
Daily	Provide fresh food (fruits, veggies, pellets, protein) & check water pools.
Every 2-3 days	Remove uneaten food to prevent mold & replace with fresh options.
Weekly	Offer calcium-rich foods (cuttlebone, crushed eggshells).
Monthly	Rotate diet to keep variety (seaweed, dried shrimp, safe plants).

The Role of Water in Survival

Since food and water are linked, it’s worth repeating: hermit crabs need both fresh and saltwater.

• Freshwater hydrates them and keeps gills moist.
• Saltwater helps them regulate molting cycles and refill their shells.
• Without water, they cannot survive more than a few days-even if food is available.

👉 For a setup guide, see our post: Hermit Crab Care for Beginners.

Common Myths About Hermit Crab Feeding

1. “Hermit crabs only eat once a week.”
   ❌ False. They may choose to skip meals, but food should be available daily.
2. “Hermit crabs don’t need water if they have moist food.”
   ❌ False. They need pools of both fresh and saltwater.
3. “Hermit crabs will eat anything.”
   ❌ False. Some foods are toxic (onion, garlic, citrus, processed snacks).
4. “If a crab isn’t eating, it must be sick.”
   ❌ Not always. Molting is the more likely reason.

Wild vs. Captive Survival Without Food

• Wild hermit crabs:
  • Adapt to food scarcity by scavenging whatever they can find.
  • Can last 1-2 weeks or longer if water is present.
  • Have access to algae, rotting plants, and decaying animals.
• Captive hermit crabs:
  • Rely 100% on the owner.
  • Tanks may lack scavenging options.
  • Without food, they weaken within days.

👉 Bottom line: captive hermit crabs cannot be treated like wild ones.

Safe Foods to Always Keep On Hand

If you’re worried about food shortages, keep a small stash of hermit-crab-friendly foods that last long:

• Dried seaweed (nori sheets)
• Unsalted peanuts or walnuts
• Dried shrimp or krill
• Coconut flakes
• Commercial hermit crab pellets
• Cuttlebone (calcium source)

These foods store well and provide essential nutrients in emergencies.

FAQs About Hermit Crabs and Food

Conclusion

So, how long can hermit crabs live without food?

While they may survive up to 1-2 weeks, this is not safe or healthy in captivity. Hermit crabs need daily access to fresh food and clean water to thrive.

Key takeaways:

• Food scarcity is dangerous, but water scarcity is fatal.
• During molting, fasting is normal-they rely on stored nutrients.
• A daily feeding routine ensures long-term health.
• Keep a backup stash of safe, long-lasting foods for emergencies.

With the right care, hermit crabs can live for 10-20 years in captivity-much longer than most people realize. A consistent feeding schedule is one of the biggest factors in helping them reach that potential.