Why are two males rabbits trying to mate with each other?

rabbits normally only fight when another rabbit or animal is trying to take its food or even its home. it also depends whether or not the rabbit is a pet or not, because if it is not a pet, it is obviously raised differently than if it was. Any rabbit, any sex, any relation and NOT altered will eventually fight as they are very territorial and they fight to establish dominance and to drive the other rabbit away.