 For nutrition, hummingbirds eat a variety of insects, including mosquitoes, fruit flies, gnats in flight or aphids on leaves and spiders in their webs.The lower beak of hummingbirds is flexible and can bend as much as 25 degrees when it widens at the base, making a larger surface for catching insects.Hummingbirds hover within insect swarms in a method called "hover-hawking" to facilitate feeding.