Hermit crabs survive by borrowing shells abandoned by other sea creatures. It's quite unusual to actually witness one switching shells, however, which is why this video is so special. What it reveals is that hermit crabs are actually quite picky about what shells they'll use — even going to far as to discard one after trying it out for a bit. Still, they are also open to trying new things, which is why one hermit crab wound up living inside half a glass bottle. Cyber-crab!