The purpose of a smoke alarm is to provide audible warning of a fire in its early stages while there’s still time for you and your family to escape safely.
Install smoke alarms inside each bedroom, outside each sleeping area and on every level of the home, including the basement. On levels without bedrooms, install alarms in the living room (or den or family room) or near the stairway to the upper level, or in both locations.
If your smoke alarm is chirping, that is a sign you need to replace it with a new CA compliant 10 year tamper proof alarm.