One of ours just up and died. All of them had been here since we bought the house like 10 years ago, so DH replaced all of them.
He says (after a lot of research) that smoke detectors have gotten a lot better in the past 10 years, so even if your smoke detector is still working, you may want to buy a new one or two.
What kind of smoke detector? The national fire prevention association recommends one that has both ionization and photoelectric smoke detection.
The kind DH got to replace our old ones was the Kidde PI2010 aka FireX 21007915 at Home Depot (where they are more expensive but we don’t have to wait for shipping).
So yeah, check your smoke detectors! It could save your life.