Foragers used and knew about hundreds of different species of plants, animals, and insects, but farmers focused on a small number of favored species, so they developed exceptionally intimate relationships with them. Intense symbiotic relationships often lead to changes in the behavior and the genetic makeup of both species. Modern honey ants “domesticate” aphids. They protect the aphids, provide them with food, and help them reproduce. Now the aphids have changed so much that they can no longer survive on their own. They pay for food
