Ants, a superorganism

The recent New York Review of Books has an article on a new book by Wilson and Hölldobler on ant societies. No surprise that my favorite line from the article is about how ants sometimes have a very strong division of labor:

In the case of the attines [an ant that farms mushrooms], however, the varying size classes have specific jobs to do. Some cut a piece from a leaf and drop it to the ground, while others carry the leaf fragment to a depot. From there others carry it to the nest, where smaller ants cut it into fragments. Then ants that are smaller still take these pieces and crush and mold them into pellets, which even smaller ants plant out with strands of fungus. Finally, the very smallest ants, known as minims, weed and tend the growing fungus bed. These minute and dedicated gardeners do get an occasional outing, however, for they are known to walk to where the leaves are being cut and hitch a ride back to the nest on a leaf fragment. Their purpose in doing this is to protect the carrier ants from parasitic flies that would otherwise attack them. Clearly, not only did the attines beat us to agriculture, but they exemplified the concept of the division of labor long before Adam Smith stated it.