Actually, some (like the one we have) don't make a flash during the day and at night us a Infrared flash that cannot be seen. The camera is ultra quiet, so you see and hear nothing. My point isn't the effectiveness of the cams at all. Rather, it's whether you would gain much useful info since by the time you check the pics, whatever was captured has come and gone. IE, you see pics of random ppl cutting your plants down after you already find your plants gone. Again, the animals at your plants or ppl you personally know being caught on cam would be the most interesting to me. Cams just show what has already happened... they don't prevent anything. That being said, I say give it a shot and post up some pics. They are definitely neat.