New ant colonies are started by a single queen that lays the eggs and tends the brood that develops into worker ants. Tending of the brood is then taken over by the workers, which shift the brood from place to place as moisture and temperature fluctuate in the nest. When workers forage for food for the queen and her young, they often enter houses and become a nuisance. They feed on animal food, grease, seeds, etc. The nests are often difficult to locate, so control is usually aimed at individual ants or groups of ants.
Ants feed on almost anything consumed by humans.