Smoke alarms have a warning beep when the battery gets low. Occasionally, back problems can give you small warning pains as well. Those should be taken just as seriously. whenever your back "chirps" call the chiropractor.
Sometimes the newer smoke detectors can collect dust on their sensors. When mine gave a false alarm, I took it down and inspected it. Ads I was looking, a tiny spider crawled out of the casing! when I called the customer service line, they admitted that tiny spiders can indeed be attracted to the electronics and can e a source of false alarms.