Just about everyone I know has had a pet hermit crab at some point when they were a kid, so most of us probably know about how they grow larger and need to switch into bigger and bigger shells. What we hadn't known until now, is that they actually will use social networking skills to locate new shells.
"When a new shell becomes available, crabs gather around it and queue up in a line from largest to smallest. Once the largest crab moves into the vacant shell, each crab in the queue swiftly switches into the newly vacated shell right in front of them. As a result, a single vacant shell kicks off an entire chain of shell vacancies that ultimately leads to many crabs getting new, and generally improved, housing."
When a crab finds a new, but oversized, shell, it will wait nearby instead of scurrying away. As more and more crabs gather around the new shell, they get to check out the real estate that will potentially become available. When one crab decides to go for it and switch, it sets off a "synchronous vacancy chain."
Full article here (redOrbit)
See it happen here! (video)