Stag beetle males give nasty nips despite massive jaws
Armed with a ferocious pair of mandibles, male stag beetles appear well prepared to take on the world. 'Their jaws are not just for ornamentation, they really use them to fight', says Jana Goyens from the University of Antwerp, Belgium, adding that males grapple over the choicest patches of rotten wood for their mates to lay their eggs in. Describing a stag beetle battle, Goyens explains that one beetle grabs the other one around its body and then rears up in an attempt to hurl his opponent over his head and onto its back. 'It is clear which one is the loser', says Goyens. But something puzzled her: 'It seemed unlikely that stag beetles could bite forcefully because they have these long jaws', she says. Instead of amplifying forces, the beetles' long mandibles would reduce the forces exerted at the sharp teeth halfway along the mandibles when gripped together. Intrigued,...