The female then builds the nest. Material used to make the nests may include grasses, leaves, bark and other plant material. Once the nest is complete, the female will lay one to two elongated, white eggs. She incubates the eggs from 14-23 days, and rears the young without the assistance of the male. In general, aggressive behavior of hummingbirds includes threat vocalizations, dives, and chasing of intruders.
Most aggressive behavior is associated with territorial defense.
Male hummingbirds typically defend feeding territories as well as breeding sites, and females defend nesting sites. A large percentage of the male's time and energy is used to defend his territory . Such defense usually begins in the air. It can include clawing, pushing, even using their bill as a weapon. It was believed at one time that hummingbirds sucked the nectar through their bills.