What is the maximum height of a fly?
What is the maximum height of a fly? On a 70 degree day, flies can reach about 3000 feet in altitude, going higher will cause death (from the cold).
Why do planes cruise at 36000 feet?
The biggest reason for flying at higher altitudes lies in fuel efficiency. The thin air creates less drag on the aircraft, which means the plane can use less fuel in order to maintain speed. Less wind resistance, more power, less effort, so to speak.