Chirping Fire Alarm 101

I'm sitting here trying to post with a f-ing chirping fire alarm. This is the second one we've had problems with. I changed the battery three times and it is still chirping. So I googled it and found out two things: first, fire alarms expire and they suggest replacing them every five years (some are even programed to chirp when they need to be replaced); second, not only are you supposed to replace the batteries twice a year (daylight savings is a good reminder) but you are supposed to vacuum dust out of them when you replace the batteries. There, now when it happens to you, you'll know. I really want to hit that alarm with a bat!!