This is a video from Nature on PBS partially shot by a spy copter disguised as a hummingbird so it can fly through a monarch butterfly swarm in Mexico with minimal disturbance. There's so many of them -- they look like flying leaves. Moths? Moths are flying dead leaves. I refuse to even donate one to Blathers in Animal Crossing because I don't want it in my museum.
Keep going for the full video while I suggest next time they try to outfit that hummer with a nicer camera because some of that footage looked like a scrambled cable channel.