Creature Feature: House Hunting, Hermit Crab-Style

By Erin Connelly and Jen Schill of the Biomimicry Institute

Trading spaces, otherwise known as a synchronous vacancy chain.
Trading spaces, otherwise known as a synchronous vacancy chain.

Have you ever wondered how hermit crabs are able to find perfectly sized shells as they grow bigger and bigger? Most hermit crabs can be as small as a few millimeters but can grow up to a few inches in length. That’s quite a big difference! Luckily, some of these organisms have found an ingenious way to find new shells, or temporary homes.

It turns out that some hermit crabs, like the Caribbean hermit crab, don’t really live up to their name. Far from solitary creatures, these hermit crabs find shells in the same way we find out about things we care about – through social networking. What’s even cooler is that their method of finding and sharing information as a community could help us humans design better ways to share resources as well.

hermit crabs
This observation of hermit crabs in Maldives was submitted to the Great Nature Project by user “monetipedone”.

So how does it work?

When a hermit crab discovers a large, empty shell, it waits nearby until more crabs gather. Once a small group is assembled, the crabs line up from largest to smallest. When the biggest crab moves into the largest shell, each crab then moves into the shell vacated by its larger neighbor. That way, one empty shell sets off what’s called a “synchronous vacancy chain,” ensuring that everyone in the group can benefit from new resources at the same time.

Can humans learn from this resourceful strategy?

Take our food system, for example. What if we could borrow the hermit crabs’ method of sharing found resources to ensure that the food we grow is distributed to where it’s needed most, or that water and other resources are used effectively? Learning how nature solves problems can show us better ways to design our world. That’s why the Biomimcry Institute invites students and professionals from all over the globe to enter the Biomimicry Global Design Challenges to  help us solve big problems (like food and agriculture issues) using nature-inspired solutions.

To solve a big design problem in their world, hermit crabs have come up with a successful community-based solution. Just imagine the possibilities if we humans could do the same.

Have you ever looked to nature for inspiration to solve a problem? You can see more examples of how to learn from nature by browsing the AskNature collection of Great Nature Project photos.

The Great Nature Project

Submit your photos of hermit crabs or any other living thing to the Great Nature Project. You can keep track of your observations and get help from other people to identify what you saw. Browse or search the photo stream to see other amazing living things. Create an account to your share your photos of plants and animals.

More to learn and do

Free classroom activities available on the Biomimicry Education Network.

Visit AskNature to find out how we might apply this cool crab strategy to make our human world more sustainable.

Check out the Biomimicry Global Design Challenges.


Erin Connelly is the communications specialist at the Biomimicry Institute, where she gets to help spread the word about nature-inspired design. Hermit crabs are now one of her favorite organisms. Jen Schill is the Institute’s AskNature content and community manager, where she gets to explore cool biology and nature-inspired innovation ideas every day. 

Erin Connelly, Biomimicry InstituteJen Schill, Biomimicry Institute

2 thoughts on “Creature Feature: House Hunting, Hermit Crab-Style

  1. this is very interesting, but my question is, how does this biggest shell get to develop to that extends? since they from one shell to another
    in “synchronous vacant chain “

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