The stag beetle is named for their impressive set of mandibles which resemble a stag’s antlers. They’re a group of about 1,200 species of beetle in the family Lucanidae. Stag beetles range in size from 2-4.8″. The male stag beetle uses its jaws to wrestle other males for favored mating sites and for females. Despite their fearsome appearance, they are not normally aggressive to humans.