Why would insects have an ecological advantage over flightless animals?

Answer 1

First it should be noted that not all insects have wings or can fly. What follows is the assumption that you mean insects that can fly. The most obvious reason is that flightless predators cannot pursue their prey in the skies. Wings also allow insects (as well as birds) to reach food which may be at a high altitude, such as fruit on a tree. Another huge advantage of flight is the ability to travel over longer distances than land-bound organisms (mainly other land-bound insects). Flight allows bees to travel great distances from their hives to find sources of food, whereas other flightless insects would not journey as far.