The hummingbirds are a family, Trochilidae, of often very small, agile birds. They are named for the humming sound produced by the rapid wingbeats they use to hover, an ability that, along with their generally long bills, allows them to feed on flower nectar, a diet they supplement with small arthropods. They are often very territorial, and after mating the male plays no role in raising the young, while the female lays two eggs in a nest she builds from materials such as lichen and spider silk.