Last night at 4:30 am the fire alarm went off in my room. I shot out of bed, grabbed my robe, and went to grab my son. The second I opened the door it stopped. There was no smoke or anything. We checked the detectors today and they don't have replaceable batteries; you just throw them out when they die. The only way it would go off is if someone pushes the "test" button. I'm super freaked out and hoping that it doesn't happen again tonight because I almost had a heart attack.