Hermit crabs differ from other crabs in that they have soft
abdomens. They’re as slow as any other crab so they have to find
an empty shell to use as a home. They’re not super choosy,
however, and will sometimes use a hollow piece of wood or stone
instead. On my recent trip to Aitutaki, we held a hermit crab
race right after lunch. One of the guides had collected a bucket
full of crabs, and drew concentric circles in the sand. We each
got to choose our champion crab, and then counted down to their
release in the centre of the circle. The crabs quickly moved
away from each other, and the crab that got to the outer ring
first was declared the winner. Contrary to their name, and their
desire in the race to run away from each other, hermit crabs are
actually quite social creatures. As they grow out of their
scavenged shells, they meet up around a new, bigger shell. When
the largest crab moves into the new shell and out of its old
shell, the next largest moves into the newly-vacated shell. This
forms a chain of he