Ants : Ron Riesenbach's Blog


I don’t know why, but lately, I’ve been studying ants.

It started with a reference in a Richard Dawkins book to the work of E.O. Wilson — the famous mymecologist (a $10 word for ant biologist). Wilson is credited with popularizing the controversial area of sociobiology – an evolutionary explanation of social behaviors such as altruism and aggression.

I have recently read a number of books on ants including The Leafcutter Ants by E.O. Wilson and Bert Holldobler and also Before The Swarm by Nicholas Griffin.

Evolution has imbued many ant species with mind-numbing social organization and economic sophistication. Some species form super-colonies with millions of individuals. These species have evolved the specialization of agriculture – they have been farming fungus millions of years. The Ants and their fungus have formed a mutualistic dependence so that particular species of fungus are only found in Ant colonies — no where else in nature. The ants form massive marching columns to go out to cut fresh leaves and stems. They don’t eat the leaves (they can’t digest it). Instead, they bring back the pieces, chew them and secrete special liquids onto the bolus, and then feed the fungus with it.  The Ants grow and eat this one specific species of fungus and the fungus uses the Ants to bring it organic matter and to weed out parasites and competing species of fungus.

Something like 99.99% of all the ants in a leaf-cutter colony are sisters. There is usually only one queen who is an egg-laying machine. She produces virtually all female workers who, according to size and age, taken on specific tasks within the colony. In some species, they switch tasks when they reach a certain size or age.

The colonies can be huge (acres of underground tunnels, chambers and air ventilation shafts) and are built up over decades.

Atta cephalotes carrying a leaf with nestmates hitching a ride

The queen will produce male and ‘royal’ offspring (female ants capable of reproduction and flight)  only a few times — right before mating season. When these princesses are ready to leave the next for their mating flight, they grab a chunk of fungus and lodge it in a special cavity under their head.

After mating, they dig a burrow, remove the fungus and start to farm it. She dosen’t eat any of it until the crop is well underway and she has produced enough daughters to tend it properly.

After studying this, I can’t help but feel humbled.