Some snakes are well-known for injecting prey with venom from their fangs. What’s less well known is that they produce toxic stuff at the other end of their bodies, too. Located at the base of the tail in venomous and nonvenomous snakes alike are glands that generate foul-smelling secretions. The point of these glands has long been a mystery, but new research suggests they could stem from a time when snakes were much less impressive and needed to protect themselves from a vicious enemy: the humble ant.