Chirp. Chirp. Chirp. Chirp. It's like Chinese Water Torture for the EARS.
Not enough sleep. Not enough sleep last night because my fire alarm started chirping its "Hey change my battery" chirp sometime in the middle of it. (It's not doing that now, though. It's flashing its "Hey everything's fine" flash like nothing happened. So what do I believe? And is it immature to want to flip the bird at a fire alarm?)