'Twas brillig, and the slithy toves did gyre and gimble in the wabe

That's the case with the smoke alarms here. It also means that when you burn the toast, *all* the alarms go off. And there's no "It's only the toast!" button on them.

Curiously the smoke alarm (actually a heat alarm) I had down had a sticker stating "This heat alarm will not operate without a working battery".