The Sound of a Crab’s Guts

Non-humans communicate through sound in more ways than an Instagram post could summarise, from the wings of a hummingbird to the rattle of rattlesnakes.

In a 2019 study published by the Royal Society, they found that the Atlantic Ghost Crab makes noise in a very unexpected way - by grinding its gut!

More specifically, this little crab makes noise by controlling its gastric mill. A gastric mill is a digestive organ that grinds food into tiny pieces before it moves to other parts of the system.

Ghost Crabs are known to make lots of noise, by stridulating their claws (that means rubbing together) and drumming on themselves or the floor. But this is the first time the rumbling of their guts has been studied.

Scientists have suggested that because these gut noises were often associated with aggressive behaviour, that the gut sounds might somehow be linked to that.

By making noise with their gastric mill, these crabs free up their claws for waving around, pinching and posturing - pretty clever really.