Members of the stag beetle family (Lucanidae) have greatly enlarged mandibles that are often forked, resembling the horns of various deer, from which their common name comes, and similar modifications appear in various scarab beetles and longhorn beetles. Males of these beetles use their mandibles to grasp or displace each other as they compete for mates.
Members of the stag beetle family (Lucanidae) exhibit notable mandible enlargement, often resembling deer antlers, which is also observed in various scarab and longhorn beetles. Males employ their mandibles for agonistic behaviors, such as grasping or displacing rivals during mate competition.