This large, fluffy-looking moth is on the wing in July and August, but you might spot a caterpillar at almost any time of year.

A fierce pirate of the sea, the Arctic skua is renowned for stealing fish from other seabirds and dive-bombing anyone that comes near its nests. It breeds in the far north of Scotland and on the…

The tree bumblebee is a new arrival to the UK. First recorded here in 2001, it is slowly spreading north. It prefers open woodland and garden habitats and can be found nesting in bird boxes and…

The marsh hair moss is the largest moss in the UK. Look out for it in damp woodland and on boggy heathlands where it forms large, green and spikey 'cushions'.

The Sitka spruce was introduced into the UK from North America in the 19th century. It has been widely planted as a forestry tree; look for classic needle-like leaves and pale brown, domed cones…

Sea potatoes may have a funny name, but they are perfectly adapted for life in the sand. They are a type of sea urchin that live in a burrow in the sand, feeding on dead animals and plants using…

These winter visitors are close relatives of the chaffinch and can often be found in the same flocks, where their white rump and nasal calls give them away.

This sponge is found on rocky shores around the UK and looks like a thick bready crust (if you use your imagination a bit!).

These moths can be seen flying on sunny days, but you're more likely to spot the fuzzy caterpillars crawling over paths.

The brent goose flies to the UK for the milder winter. Two populations arrive: those with dark bellies can be found around Eastern England; while those with pale bellies can be found in the North…