Yes. No cancer and heart disease would save millions of lives.
Yes, they ate the only mammals which could fly because flying squirrels, possums or etc. could only glide for a short distance and time, unlike bats. There are no reptiles who could fly, but there are reptiles who could glide which I think is completely different. But they said that Pterosaur existed which they believed it is a flying reptile dinosaur. Just look it up. :)
Yes it is it usually
entirely
