Many animals have cunning ways of hiding from predators. But the larva of the sand dollar takes that to an extreme – it avoids being spotted by splitting itself into two identical clones.

A pluteus can’t swim quickly, so there is no escape for one if it is attacked by a hungry fish. Instead, Dawn Vaughan and Richard Strathmann from the University of Washington discovered that the pluteus relies on not being spotted in the first place.

They exposed 4-day-old larvae to water which contained mucus from the skin of a potential predator – the Dover sole. Within 24 hours, every single larva that was exposed to the mucus has grown a small bud that eventually detached and developed into a second