Not all ant species build nests. A group of about 200 species known as army ants have two phases of their life: nomad and stationary. During the colony’s nomad phase, the ants travel all day, attacking other colonies and insects they encounter for food. At night, they build a temporary nest and keep moving the next morning. The only time they stop traveling is during the stationary phase when the queen lays eggs and the colony waits for them to hatch. During this time, the worker ants make a nest out of their own bodies to protect the queen, the food, and the eggs.