Is it possible that insects display a form of altruism so potent that it compels them to sacrifice their own lives?
Drs. Jurgen Heinze and Bartosz Walter of the Department of Biology at the University of Regensberg in Germany believe so. They have found that Moribund ants leave their nests after contracting an illness in order to die in isolation. In this way, the ants minimize exposure of the pathogen to the rest of the colony.
The researchers infected 52 worker ants with fungal spores. Of these ants, 8 died of unknown causes, but 44 left the nest within 50 hours of their death in order to die alone. Four ants did die in the nest itself – but their corpses were removed immediately afterward by other members of the colony.
Interestingly enough, this study shows also that this introverted behaviour prior to death is not solely confined to the inoculated creatures. Heinze and Walter also studied 1609 healthy worker ants in multiple colonies. It was found that a total of 13 individuals died of various causes and that 12 had left their respective colonies within 15 days of their death. The worker who died in the nest had been carried back there after spending 6 days in isolation with absolutely no contact with any other member of its colony.
Using carbon dioxide poisoning as an additional method of determining if this is more than a popular science phenomenon, researchers further discovered that the ants fared better while they were in close proximity to the nests. This leads them to believe that leaving the nest accelerates the death of the ants; it is an act that lowers their life span.
Judging by these findings, it seems to be the case that moribund ants do indeed practice a form of altruistic suicide, and that the nest conditions are necessary for the ants to survive for long periods of time. For these ants, leaving the nest is like signing their own notice of execution. However, the ants are not driven away; rather, they leave of their own accord to prevent compromising the well-being of the colony.
Well, that’s all well and good, but so what? In essence, it is the ultimate form of communism. The kind that no one follows. The health of the community is more important than the health of the individual. Take that, Stalin, next time you think about going to the doctor! Really, what this shows is that the social interactions between even such evolutionarily primitive organisms is profound. This kind of communal behaviour is sophisticated and completely voluntary. It is apparent that each one of the ants prides the survival of their community over that of their own.