The Core: The Three Foods Every Hermit Crab Should Always Have
If you've read about the Buffet Method, you already know that feeding hermit crabs is all about variety. Complete Meals change. Single Ingredients change. But one part of the buffet never does, and that's The Core.
The Core is the foundation of your crab's diet. It's made up of three things: Green Sand, Worm Castings, and Calcium. These should always be available in your crabitat, no matter what else you're serving.
Green Sand
Green sand is a natural marine mineral that contains dozens of trace minerals.
In the wild, hermit crabs spend their time digging through sand, soil, and leaf litter. Green sand gives them access to minerals they don't get from their regular food alone. Think of it as a daily mineral supplement they'd naturally encounter on the beach.
Your crabs won't eat much at one time. Instead, they'll often take small nibbles whenever they want it. Keep a small dish available at all times and let them choose when they need it.
Worm Castings
Worm castings are one of the most natural foods you can offer a hermit crab, and one of the most overlooked.
They're simply what earthworms leave behind after digesting organic matter. In nature, hermit crabs spend much of their time digging through soil and leaf litter, where they naturally come across material like this while they forage.
Offer worm castings in a small dish alongside the rest of The Core and replace them as needed.
Calcium
Calcium is one of the most important parts of a hermit crab's diet, especially around molting.
Every time a hermit crab molts, it sheds its entire exoskeleton and grows a new one. That new exoskeleton needs calcium to harden properly, which is why it should always be available.
Great calcium sources include crushed crab and lobster shell, oyster shell flour, cuttlebone, eggshell, and coral calcium. Offering several options lets your crabs choose what they need.
Why The Core Is Separate
The Buffet Method is designed to keep feeding simple, and The Core is what makes that possible.
When green sand, worm castings, and calcium are always available, you don't have to worry about whether your crabs have access to the essentials. Then you can enjoy rotating Complete Meals, proteins, fruits, vegetables, flowers, and other treats while your crabs choose what they need.
The buffet brings variety. The Core stays the same.
Nature never serves the same plate twice, but some things are always worth keeping on the table.
Ready to build your Core? Start with Green Sand, Worm Castings, and a variety of calcium sources like Crushed Crab and Lobster Shell to give your hermit crabs a strong foundation every day.
Related Guides
- What Do Hermit Crabs Eat? A Complete Feeding Guide
- Hermit Crab Molting: Signs, Stages & How to Help Your Crab Survive