Chirp

Sleeping soundly at a little after two in the morning...chirp. Chirp. I get up go into my living room and hear it again. Chirp. So I unplug or plug in all of the electronics that could be making the noise. I go back to bed. Fall asleep and chirp. Dharma, my little dog, is scared to death and shaking. I am just sleepy, and Chirp....confused. What makes that sound? Again about 5 am This time I go into the laundry room and turn off the fluorescent light. And go back to bed. It is now 7 ish and I text my son who lives upstairs to come down. And make him listen for the chirp. Chirp. He reaches up and get the smoke alarm and removes the battery, remember on The Mordern Family when Phil is going to take a baseball bat to his chirp? Yes, I remember. Do I need a base ball bat? No, just a new 9 volt battery, and a nap. And my question is, why can't they flash and not chirp?