When ants of the species Temnothorax unifasciatus get sick, they abandon their nest, walking far away from their relatives to die alone.
They perform this act of heroism to prevent the illness that is killing them from spreading to the colony.
The discovery, published in Current Biology, is the first time that such behaviour has been shown in ants or any other social insect.
By choosing to face death alone, the ants were making a truly altruistic act.
Compared to bumblebees:
… the exact opposite has been found in the bumblebee, another social insect.
Bees infected by fly larvae move out of the hive into colder air.
But in doing so, the cold temperatures slow the lifecycle of the parasite.
So the infected bees are actually trying to extend their own lives, rather than save their nest mates.
That last bit seems like a false choice, because they could be trying to both extend their own lives AND save their nest mates. Still, the trend worth noting is that scientists speak openly these days of insects “making choices” which implies minds and self-awareness. The idea of animals as creatures of “pure instinct” is rapidly fading.
Which brings me to one of my favorite scientific papers (pdf file) on bacterial cognition.
Up with anthropomorphism!