Just to piggy back on Bobby re: smoke alarms. We learned something important for our safety as well as our pets safety a couple of years ago from a friend who is a fire marshal. ALL smoke alarms, regardless of whether you change the battery regularly, are only good for 8-10 years & then they need to be replaced. The sensors lose sensitivity & even the test button does not check that the sensor works. Therefore, the entire detector needs to be replaced. Same with older carbon monoxide detectors--but end of life is 5-7 years. Many people are unaware of this (we were not aware) & end up dying in fires or due to carbon monoxide because of fire detector or carbon monoxide detector "failure".....either they do not sound or because the sensor has lost sensitivity, it is very delayed in going off & people are unable to get out in time.
Many of the newer detectors are combo smoke & carbon & have 10 year lithium ion batteries so you do not have to change the batteries like you would with the older alarms and they also have what is called an End of Life Feature. This means once you install & start it & when it hits the end of life it will chirp to let you know. You are only able to silence it for a short time (few weeks) & then it will come on & cannot be shut off so that you are forced to replace the entire unit.
We had all of ours taken out & replaced. We have since shared the info & no one was aware. I am not sure why this hasn't been a news story! Scary!