Ants use an amazing variety of food items and have bizarre nesting and food-gathering behaviors. Some are considered farmers, some gather seeds and insects, and others are straight predators. Ant species that farm generally have a stable nest site and use areas of the nest to do their farming. For example, leafcutter ants bring leaves into the nest, and these leaves are then used to grow a fungus that the ants eat. Wood ants protect and "herd" nectar-sucking insects, such as aphids, then "milk" them. When the ant strokes the aphid’s body, a sweet liquid called honeydew comes out.
Honeypot ants collect water, nectar, and insect fluids when available in their desert ecosystem. The liquid is then fed to special worker ants, called repletes, which hang from the ceiling in a special nest chamber and store the nectar in their bodies. The replete’s body expands to hold the liquid, sometimes swelling to the size of a small grape! This stored food is used by all members of the colony during lean times.
Army ants, the best known of the hunting species, may number over 700,000 in a colony. They travel to find insects, spiders, and even small mammals and reptiles to eat. The only time they stop marching and rest is while they are waiting for new eggs to hatch and pupae to emerge as adults. During this phase, the ants link their legs together and form a living nest called a bivouac, which protects the queen and her brood.