If your son asked if he could pull the fire alarm in a fire what would you say? If he was 11 and he said Dad I think there is a fire shall I pull it what would you say? What type of help would you give him so he can do it quickly?
Most smoke alarms will chirp intermittently to signal that the 9 volt battery is low. Replace all of them once a year and the problem should stop.
It is a low battery. You should change ALL the batteries.
What makes you think they will become violent. I don't see them carrying guns or calling for second amendment solutions like some group in the not so distant past.
Note really. In order not to have a build up of carbon monoxide, you need to have the vent on over the stove which would bring in cold air. I have heard of people placing a clay pot over the burner to help radiate heat better, but the carbon monoxide is orderless, tasteless, and undetectable by people until it is too late. It doesn't mater if it is either natural gas or propane. They both produce lots of carbon monoxide. You need a carbon monoxide meter (they look similar to a smoke detector, but are not the same). This will give you time to get out. Be very careful!