Its flight leads to its name: its 70 wing-beats a second cause it to buzz like a fly. It can also hover like a helicopter, and fly backwards as well as forwards: no other bird is capable of doing this.
This minute animal is warmblooded like all birds- that is, whatever the temperature may be outside, its body temperature of about 107°F remains constant.
Since it is very small, the relationship between the surface area of its body and its weight is very important. In view of the fact that its surface area is very large in relation to the bird's low body weight, the heat loss is very high. To compensate for this heat loss, it must be constantly on the move; and since in order to move it has to feed its muscles, it is forced to eat all the time.