According to the Internet (correct me if I am wrong) Mosquitoes -> stay under 25 feet but some are beefier and can go up to 130 ft Honeybees -> often under 30ft, but can go up to 10,000 if blown by winds (but they have to come back or they die) Butterfly’s and Moths -> Up to 15,000 ft comfortably using air currents
I don’t think they can “fly” fly- I think they can just like- propel themselves. Like chickens. But they can’t like— stay in the air. So I guess the answer is like- how high they can jump? Maybe 10ft at most? We know they can survive without oxygen though. So if they could actually fly higher they probably could get wayyyyyy far up into the atmosphere. Let’s be thankful they can’t.