Comprehensive tagging reveals workers switch tasks as they
age.
Because all the workers in an ant colony look the same,
tracking their movements and interactions by eye is fiendishly difficult.
Instead, Danielle Mersch and her colleagues tagged every single worker in
entire colonies and used a computer to track them, accumulating what they say
is the largest-ever data set on ant interactions.
The biologists, based at the University of Lausanne in
Switzerland, have found that the workers fall into three social groups that
perform different roles: nursing the queen and young; cleaning the colony; and
foraging for food. The different groups move around different parts of the
nest, and the insects tend to graduate from one group to another as they age,
the researchers write in a paper published today in Science1.