The Stag Beetle (Lucanus cervus) is Britain's largest insect. The male has enormous jaws that resemble antlers on a stag's head.  Although they look fearsome, they are harmless. They use their massive jaws to wrestle with other males when looking for a mate.  The Stag Beetle is now rare and endangered in Britain due to a significant loss of woodlands where they live and in addition because dead or decaying wood, which is the stag beetle larvae’s food source, is removed from forests by people.