Electronic Alarms and Home Security Devices - Detector chirping, no battery door

I don't know what kind/model detector this is. It is located just outside one of the bedrooms. :wall: When it began chirping, I assumed it needed a new battery. The cover pops off, has open slots, & printing "Do not paint". Inside, there is square black box & small circuits. One end of the box has a screw that holds it in. It can be unplugged on the other end & if done, sets of the alarm. Once you put the box back it resumes the intermitent chriping. I can not find any place for a battery nor is there any labeling indicating there is a battery. The unit is attached to the ceiling & can not be turned in either direction to try & remove it.
There is an appartment in the basement of this house. Could this detector be wird into to those & one of them need a battery? There are other detectors in the house but they are not chirping. Please help, need sleep!

Are you sure it's a smoke alarm? Some of the carbon monoxide detectors look very similar.

When it alarms when you try to take it apart, do the other smoke alarms alarm as well? Do you know what brand and model (the label is usually on the circuit board, but sometimes it's on the bottom of the mounting plate)?

I will have to wait till my son is here. I'm too short even with a step ladder to be able to read what is in the detector. Do they put carbon detectors in all electric homes? I will check to see if the other alarms sound. There is an alarm in the apt. down stairs located directly under the chirping detector. It too was chirping & I replaced that battery & it stopped chirping. But the one upstairs continues.
Thank you! Anni

Some models of smoke alarms have a little locking pin that keeps you from taking the device off the base unless it's removed. It could be as simple as a slot you insert a small screwdriver in.

Some smokes have the battery access on the bottom of the unit.