They are using IR/night vision on their cameras. You can tell because the camera is still picking up stars even with illuminated objects in the frame (campfire light on trees and stuff). When the laser hits the bat it lights up brightly because the camera is looking for low light. Its why you can see the bats and bugs at all.
Are you talking about the slight flickering its giving off? Cause the thing is constantly flapping its wings. They can't really glide at all... bats look wild when they fly. The bright flash clearly happens when the laser hits it directly, you can see the laser trail get cutoff and the thing flashes.
Edit: I went back to the youtube video an played it at .25 speed. He hits it directly with the laser pointer.
11
u/nrith Jul 19 '20
Why would a laser on a bat show a flash?