The large, dark grey water shrew lives mostly in wetland habitats. It's a good swimmer that hunts for aquatic insects and burrows into the banks.

Red squirrels are native to the UK but are a lot rarer than their grey cousins. They live in a few special places across the UK thanks to reintroduction projects.

The house sparrow is a familiar, streaky brown bird of towns, parks and gardens. Males sport a grey cap and black bib, the size of which indicates their status.

As the name suggests, this tall, white heron is considerably larger than the similar little egret. Once a rare visitor to the UK, sightings have become more common over the last few decades, with…

The Yellow slug lives up to its name - its yellow body is mottled with grey patches. Often found in gardens and damp places in houses, it can be considered a pest, but is an important nutrient…

The all-black rook is a sociable bird, so can be spotted in flocks or nesting colonies, known as 'rookeries'. Unlike the similar carrion crow, it has a grey bill and 'baggy trouser…

The Notch-horned cleg-fly isa horse fly dark grey in colour, with grey-brown mottled wings and intricately striped, iridescent eyes. There are 30 species of horse-fly in the UK; this is one of the…

Barnacles are so common on our rocky shores that you've probably never really noticed them. They're the little grey bumps covering the rocks that hurt your feet when you're…

The common carp is a very large fish that is popular with anglers due to its size and fighting spirit. It frequents ponds, gravel pits and lakes, but is not native to the UK, being introduced in…

The glow-worm is not actually a worm, but a beetle. Males look like typical beetles, but the nightly glow of a female is unmistakeable - lighting up to attract a mate in the darkness of their…