Ants and the Buggers from Ender's Game have one important thing in common: The ability to selflessly commit their lives to the good of the colony. Social ants build nests, collect food, and defend the colony. Most ants don't reproduce, but will spend their lives helping raise non-descendant young. Their altruistic social behaviors have clearly paid off, as there are estimated to be over 20,000 species and 10,000,000,000,000,000 (that's 10 quadrillion!) individual ants in the world.
Researchers have found yet another way in which ants selflessly sacrifice their lives for the good of the colony, this time literally. Temnothorax unifasciatus ant workers infected by a fungal pathogen leave the nest hours or even days before an imminent death, to die in isolation far from the colony in order to prevent the spread of infection as well as the waste of resources. The life-span of ants who left the nest to die in isolation can be up to days shorter, further proving the altruistic nature of the worker. While some species of ants have specialized workers (evolved with special resistance to fungal disease, cool!) who dispose of sick and dying ants, T. unifasciatus ants voluntarily leave the colony.
Because of the immense (no kidding) amounts of inter-relatedness within a colony, susceptibility to disease is a very limiting factor within colonies. In order to cope with this, ants have developed a social evolution (!!!) which has allowed them to extend colony success and growth. While there are many other ways in which ants have socially evolved to compensate for this danger, T. unifasciatus ants have developed a method of altruistic sacrifice which reflects a desire for the success of a colony over the success of an individual, and... is truly inspirational.