Living up to its name the Common blue damselfly is both very common and very blue. It regularly visits gardens - try digging a wildlife-friendly pond to attract damselflies and dragonflies.

Violet ground beetles are active predators, coming out at night to hunt slugs and other invertebrates in gardens, woodlands and meadows.

This secretive bird is a member of the rail family, related to coots and moorhens. The breeding call, a rasping rattle, is given mostly at night, sometimes for hours on end.

The melodious song of the nightingale is the most likely sign of this bird being about. Shy and secretive, it sings from dense scrub and woodland, day and night.

A delicate, small plant of woodlands and hedgerows, wood-sorrel has distinctive, trefoil leaves and white flowers with purple veins; both fold up at night.

Famed for its tapping in the middle of the night, supposedly heralding tragedy, the Deathwatch beetle is a serious wood-boring pest. In houses, their tunnelling can cause major damage.