yes and no. sometimes it spooks them, sometimes it doesn't. when it does spook them i don't think it's too bad, they just kind of move away pretty quickly and then go back to what they were doing. i've seen my cameras take pictures of deer several times while hunting. i even saw a fawn come up and lick my camera. it took a pictures mid lick. the fawn jumped a bit but came right back up to the camera. but those are fawns and they are dumb as can be.

i've read that if the flash is over the deer's head they think of it as lightning and don't get spooked as bad as if the camera was at eye level or lower. not sure if i buy it though.