Not frantic at all,
they're one of the most graceful and athletic flyers in the sky. They fill the same niche as bats, but they fly higher, faster and only slightly less maneuverable. They are a joy to watch. and for some reason, its really comforting to see or hear them around. You can only see them for the few minutes between sunset and dark, but you hear their distinctive shrieks all night.
They are also called nightjars or goatsuckers, although as far as I know, they are not related to chupacabras.