Male stag beetles expend valuable energy testing one another in battle. At the feeding places the male fights occur, in which rivals try to make each other to lose balance , and that use to finish with expulsion of one of the fighters. The biggest stagbeetle is Prosopocoilus giraffa keisukei from Flores (Indonesia), . It can reach up to 12,4 cm! Pictured is another very impressive stagbeetle from Palawan (Philippines) : Dorcus titanus - with males up to 11,1 cm.