Among E.O. Wilson's many fine qualities is his status as one of the world's foremost authorities on ants (a myrmecologist). His seven-pound masterwork, The Ants (cowritten with Bert Holldobler) is perhaps the most definitive text on a single organism ever written. I have Wilson and Holldobler's smaller, more accessible version written a few years later for general readers, The Journey of the Ants. The "superorganism" aspect of ants fascinates me, even as I'm cursing them in my kitchen.
Yet I learned more about ants from reading Wilson's 6200-word short story "Trailhead" (in the Jan 25 New Yorker magazine) than I have from any of the technical books or articles I've read (or, you know, skimmed). There's a good lesson here for people who need to communicate complex information: because Wilson took his vast knowledge and put it into a narrative, even including the biological details help to propel the story of the life cycle of a colony.
Because ants live most of their lives in underground darkness, they cannot communicate through sight or sound. Pheromonal, they think only in taste and smell. The members of the Trailhead Colony transmitted their messages using about a dozen chemical signals, which they picked up by smelling one another constantly with sweeps of their antennae. An ant who was well fed said to a less well-fed nest mate, Smell this, and if you are hungry eat. If the ant approached and was in fact hungry, she extended her tongue, and the donor ant rewarded her by regurgitating liquid directly into her mouth. When a wood thrush flew by the Trailhead mound carrying a grasshopper to her own nest and dropped part of the crushed insect to the ground, a patrolling worker found it in less than a minute and triggered a chain action. The worker examined the grasshopper, tasted it briefly, then ran back to the nest entrance. On the way, she touched the tip of her abdomen repeatedly to the ground, laying down a thin trail of chemicals. Entering the nest, she rushed up to each nest mate she passed, brushing her face close to theirs. With their antennae, her nest mates detected both the trail substance and the smell of grasshopper. The signals now proclaimed, Food. I have found food. Follow my trail! Soon a mob of ants ran out, followed the trail, and gathered around the delicious grasshopper haunch. Some of the first to arrive ran back to the nest, laying trails of their own, reinforcing the message, saying, Come on, come on, we need help. The ants still by the grasshopper piece began to drag it toward the nest entrance. A catbird perched on the branch of a nearby tree saw the activity and swept down to investigate. She pecked at the grasshopper, scattering the ants and injuring several. The ants expelled a pheromone from a gland that opened at the base of their jaws. A chemical vapor spread fast. It shouted, Danger! Emergency! Run!
