Males' Oversize Right Claw Lures Crustacean Ladies

If she's Dulichiella appendiculata — a tiny relative of the sand-hopping beach flea — she's impressed by the size of the male's enlarged right front claw, which is significantly bigger than its left one. And she definitely prefers righties to lefties. Scientists have investigated the mating success of right-clawed D. appendiculata males versus their left-clawed rivals, and found that righty males attracted more females.