It is thought that most predators are a threat mainly to young mandrills, with the likelihood of predation decreasing in adult females and especially adult males, which may be invulnerable to all but the rare ambush by a leopard. In a study where a mandrill troop was exposed to stimuli relating to their natural predators, only the leopard caused the larger part of the group to flee into trees. However, the large, dominant males were observed to remain in response to the images of the natural predators, even the leopard, and pace back and forth while baring their teeth, generally indicating aggression and the defensive role they may play in such circumstances.[29][30][31][32][33]