I just read this story on NPR about exploding ants! When scientists grabbed the ants with forceps they would explode.
Apparently, they become Kamikaze ants even in the presence of the other ants to protect their colony from afar. This works because, once the ants explode, they are permanently stuck to their ant opponent, making the opponent vulnerable to other predators. Imagine being by that ant nest!
Malaysian exploding ant: