What is the Complete Hermit Crab Diet and Feeding Guide?

Feeding your hermit crab correctly is one of the most confusing, yet vital, parts of being a good crab parent.

After caring for my five crabs for years, I’ve learned through trial and error how to build a thriving diet that keeps them active and healthy.

The single best piece of advice I can give you is that variety is not just nice, it is non-negotiable for their survival.

In this guide, we will cover the core components of their diet, a simple feeding schedule, dangerous foods to avoid, and the critical role of water.

Understanding Hermit Crab Dietary Needs

Feeding your hermit crab goes far beyond a scoop of commercial pellets. In my years of caring for my crew, I’ve learned their wild diet is incredibly diverse, and mimicking that variety is the key to a thriving crab. They are natural scavengers, and their nutritional needs are complex (especially when it comes to proteins and insects).

Core Food Groups for a Balanced Diet

Think of your crab’s plate like a colorful buffet. A balanced diet prevents nutritional deficiencies that can lead to lethargy, poor molting, and a shortened lifespan. I rotate these groups daily to keep my crabs interested and healthy.

Proteins: Building Blocks for Health

Protein is non-negotiable, especially for growth and a successful molt. I offer a protein source every single day, and I watch crabs like my assertive Zeus immediately claim these spots. They need it for building new exoskeleton and repairing tissue.

• Unsalted nuts and seeds (crushed almonds, sesame seeds)
• Plain cooked shrimp, fish, or chicken (no seasoning)
• Mealworms or crickets (freeze-dried or live)
• Eggs (hard-boiled and chopped, including the shell for extra calcium)
• Unseasoned organic peanut butter (a tiny smear)

Fruits and Vegetables: Essential Vitamins

This group provides crucial vitamins, fiber, and hydration. My crab Apollo will pass on leafy greens for a piece of sweet fruit any day, so I have to get creative to ensure he eats his veggies. Always use organic when possible and wash everything thoroughly.

• Favorites in my tank: Mango, banana, coconut, papaya, and apples.
• Vital Veggies: Sweet potato, carrot, spinach, kale, and broccoli.
• Remove uneaten fresh food within 24 hours to prevent mold.

Essential Nutrients for Optimal Health

Beyond just food groups, you need to think about the specific nutrients inside them. A crab’s body is a complex system that relies on a precise balance of macros and micros to function correctly. Getting this right means you’ll see more activity and brighter colors.

Macro Nutrients: Proteins, Fats, Carbs

These are the nutrients your crabs need in the largest amounts for energy and structure.

• Proteins: As discussed, this is for growth and molting. Without enough, a crab can become stuck during a molt.
• Fats: Provides concentrated energy. Found in nuts, seeds, and some fish. I see a noticeable energy boost in my crabs after they’ve eaten foods like flaxseed or chia seeds.
• Carbohydrates: The main energy source. Found in fruits, vegetables, and whole grains like oats.

Micro Nutrients: Calcium and Vitamins

These are needed in smaller amounts, but they are absolutely critical.

• Calcium: This is the most important micronutrient. A constant calcium source is mandatory for building and maintaining a strong exoskeleton and shell. I keep a cuttlebone in the tank at all times.
• Sources: Cuttlebone, crushed oyster shell, crushed eggshell, and calcium-rich vegetables like kale.
• Vitamins: A varied diet of fruits, vegetables, and proteins typically covers their vitamin needs. Carotenoids from foods like carrots and shrimp help maintain their vibrant shell and skin color.

Step-by-Step Feeding Instructions

Getting into a good feeding routine is one of the best things you can do for your crab’s health. I’ve found that a consistent schedule and a well-prepared meal make a world of difference in their activity and shell-changing habits. Let’s break down exactly how to get food to your crabs.

Portion Sizes and Frequency

Overfeeding is a common mistake that can attract pests and mold. A good rule of thumb is to offer a small amount of food each evening. The “one crab, one teaspoon” guideline has never failed me-it’s just enough for them to eat overnight without leaving a big mess.

Here is a simple chart based on the number of crabs in your tank:

Number of Crabs	Recommended Portion
1-2 Crabs	1-2 teaspoons of food
3-5 Crabs	1 heaping tablespoon of food
6+ Crabs	1.5-2 tablespoons of food

Remove any uneaten food in the morning to keep the tank clean. This daily spot-cleaning prevents bacterial growth and lets you monitor what they are actually eating. I do this first thing with my coffee-it’s a peaceful little ritual.

Meal Preparation and Tips

You don’t need a gourmet kitchen, but a little prep makes their food safer and more enticing. Properly preparing their meals ensures they can actually eat and absorb the nutrients you’re providing.

Follow these steps for perfect hermit crab meals every time:

1. Rehydrate Dry Foods: Soak pellets, dried shrimp, or mealworms in a teaspoon of treated dechlorinated water for five minutes. This makes them easier to eat and digest.
2. Chop Fresh Foods: Cut vegetables and fruits into pieces smaller than their shell opening. My crab Apollo can’t handle big chunks of carrot, but tiny slivers disappear quickly.
3. Create a Mix: Combine a protein, a vegetable, a fruit, and a calcium source on a small dish or shell. Variety in every meal is key.
4. Offer Supplements Separately: Place cuttlebone or crushed eggshell in a permanent spot in the tank. They will self-regulate their calcium intake as needed.

A few extra tips from my experience:

• Rotate protein sources weekly-one week use shrimp, the next week use bloodworms-to cover all their nutritional bases.
• Lightly steam hard vegetables like sweet potato to soften them, making the nutrients more accessible.
• Use clean seashells as food dishes. They look natural and are easy to clean and replace.

Watching your crabs eagerly scuttle over to a freshly prepared meal is one of the most rewarding parts of being an owner.

Safe vs. Toxic Foods: What to Avoid

Getting their diet right is one of the most impactful things you can do for your crab’s health. I learned this the hard way early on when one of my first crabs, Zeus, got into some food he shouldn’t have. Providing a balanced and safe menu is non-negotiable for their well-being. Knowing which human foods hermit crabs can eat safely is part of that care. When in doubt, stick to small, unseasoned fruits and vegetables along with plain proteins and avoid processed snacks.

Safe Foods List

In my tank, I rotate through these staple categories to keep my crew healthy and excited for mealtime. Variety truly is the spice of life for them.

• Quality Proteins: Unsalted raw shrimp, freeze-dried plankton, plain cooked chicken, and bloodworms are favorites. My crab Apollo goes wild for a piece of scrambled egg with the shell left on for extra calcium.
• Fresh Fruits & Veggies: I offer small pieces of mango, banana, apple, coconut, sweet potato, and carrots. Athena, my calm observer, always makes a beeline for chopped zucchini.
• Leafy Greens & Others: I occasionally add organic spinach, kale, and seaweed (nori) to their food dish. They also enjoy unsalted nuts like almonds and walnuts, cracked open.
• Essential Calcium: This is crucial for strong shells. I always keep cuttlebone in the tank, and I also offer crushed oyster shell and eggshells that I’ve baked and crushed.

Toxic Foods to Steer Clear Of

Just as important as knowing what to feed is knowing what to keep far away from your tank. Their systems are delicate and cannot process many common foods.

• Anything with Salt or Seasonings: This includes chips, pretzels, and processed human foods. Salt is extremely dangerous and can be fatal. I’m extra careful to never handle their food after touching salty snacks.
• Onions, Garlic, and Chives: These members of the allium family can cause digestive issues and blood cell damage in hermit crabs.
• Citrus Fruits: The high acidity in oranges, lemons, and limes is too harsh for their stomachs and can cause irritation.
• Pineapple & Highly Acidic Foods: Similar to citrus, the acidity can be problematic and may even contribute to shell damage over time.
• Processed Sugars and Chocolate: Candy, chocolate, and sugary cereals offer no nutritional value and can lead to serious health problems.
• Pesticides: Always wash all fruits and vegetables thoroughly to remove any pesticide residue, as it is highly toxic to them. I make a habit of buying organic when I can, especially for their thin-skinned favorites.
• Treated Wood and Plants: Never forage wood or leaves from areas that may have been sprayed with herbicides or pesticides.

Best Food Choices: Commercial and Homemade

After years of feeding my own crew-Hermes, Apollo, Athena, Zeus, and Poseidon-I’ve learned that variety is the absolute key to a thriving crab. A diverse diet prevents nutritional deficiencies and keeps your crabs excited to eat. I like to think of their meals as a tiny, rotating buffet.

Evaluating Commercial Hermit Crab Food

Walking down the pet store aisle can be overwhelming. Many commercial foods are packed with fillers and preservatives that offer little nutritional value. I always check the ingredient list before buying anything.

Here is what I look for in a high-quality commercial food:

• Named Protein Sources: The first ingredient should be something like “fish meal,” “shrimp,” or “mealworms,” not “grain products” or “plant protein.”
• Calcium Supplementation: Look for calcium carbonate or crushed oyster shell in the ingredients. This is non-negotiable for strong exoskeletons.
• Minimal Preservatives: Avoid foods with ethoxyquin, BHT, or BHA. These can be harmful over time.
• No Copper Sulfate: Hermit crabs are incredibly sensitive to copper, and this common additive can be toxic to them.

My personal rule is to use commercial food as a reliable base, not the entire meal. I mix a high-quality pellet with a mountain of fresh foods to create a balanced plate. This ensures my crabs get consistent nutrients while enjoying the sensory experience of different textures and flavors.

Homemade Recipes for Variety

This is where the real fun begins for you and your crabs! Making your own food mixes is cost-effective and lets you control exactly what goes into their bodies. My crab Apollo goes wild for these homemade blends.

I always keep these staple ingredients on hand for quick meals:

• Proteins: Unsalted raw shrimp, dried mealworms, plain cooked chicken, and scrambled egg (with the shell crushed in for calcium).
• Vegetables: Sweet potato, carrots, broccoli, and leafy greens like kale and spinach.
• Fruits: Mango, banana, coconut flakes, and apples (all served fresh).
• Extras: Unsalted nuts (crushed), seaweed (nori), and plain popcorn.

Here is a simple, nutrient-packed recipe my crabs devour every time. I call it the “Shell-Strengthener Mix.”

1. Start with a base of ¼ cup of organic rolled oats.
2. Add two tablespoons of crushed, plain cuttlebone.
3. Mix in one tablespoon of dried shrimp and one tablespoon of crushed almonds.
4. Finish with one teaspoon of bee pollen and a sprinkle of dried seaweed flakes.
5. Store the dry mix in an airtight container. When serving, I moisten a small spoonful with dechlorinated water or a bit of raw honey.

Offering a wide range of textures and smells stimulates natural foraging behavior. I’ve watched my shy crab, Athena, become much more active since I started presenting food this way. Remember to remove any uneaten fresh food within 24 hours to keep the habitat clean and mold-free.

Species and Age-Specific Feeding Tips

Feeding your hermit crabs is not a one-size-fits-all task. What and how you feed them should change based on their life stage and species type. I’ve adjusted my own feeding strategies over the years as my crab crew, Hermes, Apollo, Athena, Zeus, and Poseidon, have grown and shown me their unique needs. Understanding their dietary requirements is crucial.

Juvenile vs. Adult Hermit Crabs

Young, growing crabs have very different nutritional demands compared to their older tank mates. Getting this right supports healthy molting, which is the most critical and dangerous part of their lives.

• Protein is Paramount for Juveniles: I always offer my younger crabs, like Poseidon, a high-protein food daily. Their bodies are building new exoskeleton at a rapid pace. Good sources include dried shrimp, bloodworms, and a tiny bit of plain, cooked chicken or fish.
• Adults Thrive on Variety: My older crabs, like Zeus and Athena, get a protein-rich meal every other day. On off days, I focus on complex carbohydrates and calcium. This prevents obesity while still meeting their nutritional needs for shell and exoskeleton maintenance.
• Calcium Availability is Non-Negotiable: Both juveniles and adults need constant access to calcium. I keep a cuttlebone in the tank at all times. For juveniles, I also sprinkle a calcium powder (without D3) over their food more frequently to support that intense shell growth.
• Monitor Feeding Frequency: Juveniles seem to have faster metabolisms. I notice food disappears quicker when my younger crabs are active. I offer smaller amounts of food more frequently to ensure they always have access to nutrients without spoiling the tank.

Species-Specific Dietary Preferences

Just like dogs have different breeds, hermit crabs have species-specific traits that influence their eating habits. Observing my own group has been a masterclass in this, especially when considering the science of hermit crab digestion and nutrition.

• Caribbean Hermit Crabs (Hermes, Zeus, Poseidon): These are often the most adventurous eaters. My Caribbeans are bold and will readily try any new fruit, vegetable, or protein I offer. Zeus, in particular, is drawn to strong-smelling foods like salmon and eggshells.
• Ecuadorian Hermit Crab (Apollo): This species is known for being especially fond of cellulose. I always make sure Apollo has plenty of safe, untreated tree bark, oak leaves, and cholla wood to munch on. He spends more time grazing on these fibrous materials than any of my other crabs.
• Strawberry Hermit Crab (Athena): Strawberries have a reputation for being slightly more delicate. I find Athena prefers sweeter fruits like mango, papaya, and banana over leafy greens. She is also my most cautious eater, often waiting for the other crabs to try a new food before she approaches.

The key is to become a keen observer. You will start to see clear patterns in which foods certain crabs gravitate towards first. Use those observations to tailor the placement and variety in the dish, ensuring every crab gets what it needs to thrive.

Troubleshooting Common Feeding Issues

Even with the best intentions, you might run into some snags with your crab’s eating habits. I’ve found that observing their behavior closely is the single best way to catch problems early, before they become serious health concerns.

Signs of Nutritional Deficiencies

Your crabs can’t tell you they feel unwell, but their bodies send clear signals. Watch for these red flags that often point to a poor diet.

• Slow, Lethargic Movement: A crab that is consistently inactive or seems weak might not be getting enough energy from its food.
• Pale Coloration: Dull, faded colors can indicate a lack of carotenoids, which are found in foods like red bell peppers and carrots.
• Difficulty Molting: If a crab struggles to shed its exoskeleton or the new one underneath is soft for too long, it’s often a calcium deficiency.
• Nibbling on Other Crabs: Cannibalistic behavior is a desperate attempt to get protein and minerals they are missing from their meals.
• Loss of Appendages: A crab dropping a leg or claw can be a sign of extreme stress or malnutrition.

When my crab Apollo went through a phase of being unusually still, I immediately boosted his protein with some dried shrimp and offered a cuttlebone. Providing a constant source of calcium, like a piece of cuttlebone in the tank, is one of the easiest and most effective ways to prevent a host of common issues primarily related to their health and shell strength.

Handling Molting and Feeding Changes

Molting is the most stressful and dangerous time in a hermit crab’s life. Their feeding behavior will change dramatically, and knowing what to expect is vital. If you notice signs of hermit crab stress (reduced movement, hiding, or erratic behavior), you’ll know what to do. Keep humidity and temperature stable, minimize handling, and provide a safe molt site.

You’ll notice the signs before the molt even happens. Your crab might:

• Eat and drink excessively to store energy.
• Become more reclusive and dig down into the substrate.
• Lose interest in its favorite foods.

Once your crab buries itself to molt, the rules change completely.

1. Do Not Disturb: You must not dig for your crab. It is vulnerable and any disturbance can cause fatal stress.
2. Leave Food and Water: Continue to place fresh food and dechlorinated water on the surface. The crab may surface briefly to eat and drink before its new exoskeleton hardens.
3. Focus on Post-Molt Nutrition: When your crab resurfaces, it will be ravenous. Offer high-protein and high-calcium foods immediately to help it regain strength and harden its new shell. I always give my crabs a special post-molt meal of crushed eggshell, bloodworms, and a bit of honey for energy.

I learned this the hard way with my crab Zeus, who once molted and came up to find his siblings had eaten all the good food. Always ensure there is plenty of nutritious food available for a crab when it finishes molting, as it will be at its weakest and most hungry state.

FAQs

Why isn’t my hermit crab eating the food I provide?

Hermit crabs are primarily nocturnal, so they often feed at night when you cannot see them. They also have small appetites, so the small portion sizes recommended may simply be consumed before you check in the morning. Follow the feeding guide for portions and frequency: offer a small amount that can be eaten in a few hours, usually once daily. Adjust the amount based on species and number of crabs.

What is the difference between the saltwater and freshwater dishes?

Both are essential, as hermit crabs need freshwater for hydration and saltwater for osmoregulation and shell health. You must use dechlorinated water for the freshwater dish and a marine-grade aquarium salt mix for the saltwater, never table salt. Proper water and moisture conditions are crucial for maintaining a healthy habitat for hermit crabs.

How should I store my hermit crab’s food to keep it fresh?

Store dry commercial and homemade food mixes in airtight containers in a cool, dark place to preserve nutrients and prevent pests. Always remove uneaten fresh fruits and vegetables from the habitat within 24 hours to prevent mold and bacterial growth.

In Closing

Providing a varied, balanced diet is the single most impactful thing you can do for your crab’s health and longevity. Think of their food bowl as a tiny, rotating buffet of proteins, fruits, vegetables, and essential calcium. A consistent feeding routine with fresh foods and saltwater will keep your curious shelled friends thriving for years to come. To create a hermit crab diet plan from scratch, outline a weekly rotation of safe proteins, produce, and calcium sources. Start with small portions and observe how your crabs respond.

Further Reading & Sources

• r/hermitcrabs on Reddit: What do hermit crabs eat?
• What Do Hermit Crabs Eat?
• How to Spoil Your Hermit Crabs: Food Edition : 11 Steps (with Pictures) – Instructables