One of the most colourful fish in UK seas, the cuckoo wrasse looks like it belongs in the tropics. Don't be fooled though, it's very much a native species.

The White-clawed crayfish is a freshwater, bronze-coloured crustacean with pale undersides to its claws - hence the name. It is under threat from an invasive and introduced species of crayfish.…

Buddleia is a familiar shrub, well-known for its attractiveness to butterflies. It is actually an introduced species, however, that has become naturalised on waste ground, railway cuttings and in…

Sand sedge is an important feature of our coastal sand dunes, helping to stabilise the dunes, which allows them to grow up and become colonised by other species.

Traditionally a coastal species, Lesser sea-spurrey has spread inland, taking advantage of the winter-salting of our roads. Its pink-and-white flowers bloom in summer.

The fearsome-looking hornet may not be a well-loved insect, but it is actually much less aggressive than the common wasp. It is also an important pollinator and a predator of species that feed on…

With a silvery body, and purple, pink and bluish streaks down its flanks, the rainbow trout lives up to its name. Popular with anglers, it is actually an introduced species in the UK.

The Common sexton beetle is one of several burying beetle species in the UK. An undertaker of the animal world, it buries dead animals like mice and birds, and feeds and breeds on the corpses.

The Natterer's bat can found across the UK, although it is a scarce species. It prefers to forage low down among trees, often taking prey directly from the foliage.

A plump gamebird, the red-legged partridge is an introduced species that seems to have settled here with little problem. It can be spotted in its favoured open scrub and farmland habitats.

The carnivorous lifestyle of the round-leaved sundew makes this heathland plant a fascinating species. The round leaves have sticky, 'dew'-covered tendrils that tempt in unsuspecting…