Transcript:

Here’s a program from our archives. We humans are not the only ones who keep herds of domesticated animals. Ants have been practicing animal husbandry for millenia. I'm Jim Metzner and this is the Pulse of the Planet. ambience, ant stridulations Right now we're listening to highly amplified sounds of a colony of ants. Edward Wilson is Baird Professor of Science and Curator of Entomology at Harvard University. Wilson: Some kinds of ants engage in what can fairly be called animal husbandry. That is to say, they keep domestic animals in the form of aphids, or similar creatures called mealy bugs or scale insects, on roots of plant growing in their nest, or on plants growing outside near the nest. And they assidously attend these cattle of theirs, guarding them from insects that would otherwise capture them and eat them, and milking them for the sugary excrement that these particular kinds of creatures produce. Aphids, for example, suck up plant sap. They process it in their gut. They take some of the nutrients for themselves, and they pass out other nutrients in the forms of sugar and amino acids, which comes out of the ends of their abdomens in the form of droplets of sweet liquid called honeydew. The ants then keep these insects and harvest the honeydew as a major source of their food. They also carry these insects around, from one place to another, building up the population of their cattle, and some of the most dominant, aggressive and successful ants in the world are some of these cattle tenders, these experts in animal husbandry. This archival program is part of our thirtieth anniversary celebration. If you want hear more, check out our podcast. music