Since writing about E.O. Wilson's novel Anthill, with its allegations that there are fundamental similarities between people and hive insects, I've spent quite a lot of time over the past couple of weeks looking at ants. I was on holiday, on one of the less salubrious but more convenient stretches of the Italian seaside, and as the beach was off-limits for much of the time – bad things can happen to five-month-old babies in the midday sun – spent several hours each day in the shade of a mimosa tree, reading books by Maile Meloy (review forthcoming) and watching the lines of ants scurrying across the yard between their nests and such scavengeables as a breadcrumb or a dead wasp, pausing occasionally to exchange pheromones with their colleagues going the other way.