Hermit Crab vs. Conch
The giant horse conch weighs over eleven pounds – that's a lot of mollusk.
The conch has a taste for snails, so when the tiny tulip snail spots one of these behemoths, it knows it's in trouble. The snail tries to outrun the big hunter, but it's like a tiny shuttle facing off with a star destroyer in a battle that moves at a snails-pace. Finally, it's over-run.
The smell of digesting snail attracts new scavengers – hermit crabs. Instantly, the big conch is surrounded, but the crabs aren't here for leftover escargot. They're after the tulip snail's shell.
Hermit crabs use cast-off shells to protect their soft abdomens from predators. They find an empty shell, use their rear legs to attach to its central column, and move right in. When their current homes grow tight, they have to look for new real estate – the competition is fierce.
With the conch ready to release the shell, the housing battle heats up – until one crab decides to jump in and close the deal. It's a risky move – the big conch could still be hungry – but the risk pays off. The crafty crab will have plenty of room to grow in his new home. The losing crabs could end up homeless – or worse.
Learn more at National Geographic