Hummingbirds are a family of fast and aerobatic, nectarivorous and somewhat insectivorous birds from the family Trochilidae. They are closely related to swifts. They have colourful heads, and their heart can beat at over 90bps. They have a high metabolism speed to support their lifestyle, as well as the highest flapping rate of any extant bird. They are incredibly small and light, requiring their weight in nectar every day to survive.