The bat, the only flying mammal
This small animal the size of a sparrow is the only mammal that can fly. They are as small as a bee and so large that they measure up to 1 meter.
They are practically blind, but they compensate with an extraordinary ear. They make a sound and, when they bounce (the echo), they receive information about what they have around them and they measure distances. It is very similar to the radar system of aircraft.
Vampire bats have almost no accumulated fat in the body; therefore, if they do not eat in three days, they die. They need 15 grams of blood a day, almost half of their own weight.