In order to help protect close relatives, termites have been found to explode during fights, bees die after stinging, while the members of another species of ant have been found to condemn themselves to death by sealing in a nesting colony from the outside.

BBC: Earth News - Heroic altruistic ants face death alone to save colony

They tried the ant plant, both with and without ants, and another acacia plant, also with and without ants.

BBC: Ants work with acacia trees to prevent elephant damage

Nigel Raine, another ecologist from Royal Holloway, University of London, also studies these ant plants, and says that giraffes will go ahead and eat the leaves of the plants, although ants will then swarm onto their face and mouth and try to bite them.

BBC: Ants work with acacia trees to prevent elephant damage