There was a story on the BBC last week, reporting on findings that leaf-cutter ants have socially age-related division of labor that is beyond their genetically programmed cast structure. This comes from a paper in Behavioral Ecology and Sociobiology. When their leaf-cutting jaws wear dull, the ants change jobs, from cutting to transporting the cuttings of others back to the nest. It isn't clear if this is done by choice or by some sort of coercion by sharper ants, but seems to the investigators to be voluntary. It's finding a useful role for the good of the society.
The study leaves many questions open, since the investigators appear to have compared lab ants' jaws to those in the wild, and they say that those with really blunt (90% reduced) cutter jaws 'exclusively' transported things back home. Naturally, rather than stick with an interesting story, the authors have to start speculating about what this was adapted for and all that. Like the idea that the ants 'may' have longer life spans than solitary species (so many questions about what comparisons to make and what kind of data actually count, and what determines lifespan in the wild and how strongly, are opened that we'll pass on further comments).
But why this blunt before the retirement from cutting, if this is an evolutionary adaptation? Why wait? And do ants always transport what they cut, or do they cut and transport in mixed behavior, transporting when their jaws get tired, and if so, perhaps the dull ants actually keep trying to cut but then when jaw-rest time arrives they pick up a piece and haul it home? To make darwinian speculation, questions like these must be answered, and undoubtedly we could think of others. But that won't dull the interest in the role-playing observations themselves.
This facultative action shows yet again the sophisticated abilities of the miniscule brains (if that's where the decision is made) of these amazing creatures. It's another chapter in the antidote for the narcissstic view we have, even in science, of our abilities and the notion of our uniqueness in Nature. Yes, we're unique, but so are crabs, ants, and oaks.