A robot crab has helped scientists understand how male fiddler crabs compete over females. Male fiddler crabs have one oversized claw, and they attract females by standing outside their burrow and waving it. In the

A robot crab has helped scientists understand how male fiddler crabs compete over females.

Male fiddler crabs have one oversized claw, and they attract females by standing outside their burrow and waving it.

In the new study, a robot crab – nicknamed Wavy Dave – waved its claw on a mudflat teeming with male fiddler crabs.