Ruby-throated hummingbirds eat insects and nectar from many flowering plants. They are attracted to the colour red.

Ruby-throated Hummingbirds nest from March to July and may raise anywhere from one to three broods of young throughout that time. The young are ready to leave the nest when they are twenty to twenty-two days old.

In flight, their wings move so rapidly that they are a blur. When hovering, their wings beat 55 times a second. When they are backing up, their wings beat 61 times a second. When they are flying forward, their wings beat 75 times a second.