Beetles have sexual reproduction, and almost all go through complete metamorphosis. Some beetles have complex behavior to get a mate. Pheromones are used, and different species use different pheromones. Before reproduction, some male beetles sometimes fight to claim a female. This especially happens with stag beetles: males will fight using their long mandibles. More often, male and female beetle go through a long routine before mating. The details differ in each species and that is the point. It is essential that mating takes place between beetles of the same species.