Not likely to be glow-worms, not in UK anyway. They are beetles living in rough grass, especially on downland and heathland. They eat snails, and are usually seen in warm summer weather.
They don't come indoors, in Britain, though I have seen them indoors (glowing under the bedsheet!) in Majorca.
There are other firefly and glow-worm species elsewhere, and I don't know what they do.
Lindy -- any time the urge for vacuuming comes on, let me know and you can drop round...