Do you know why geese fly in flocks? I think it’s because when a goose catches a glimpse of its own reflection, it doesn’t believe that a bowling ball with wings could possibly get off the ground. They all depend on each other to prove to themselves that they can actually fly.
How about monkeys? Have you ever seen a monkey picking the bugs off its own back? I don’t think so, and that’s why monkeys stay together in packs. If bees didn’t swarm, we wouldn’t have honey. If ants didn’t colonize, we wouldn’t have dirt piles jutting out from cracks in our sidewalks. And if moths weren’t looking for places to congregate annoyingly on warm summer nights, why would any of us have front-porch lights?