Despite its name, the great spider crab is actually smaller than the more common European spider crab.

Largely confined to the north of the UK, the rare pine marten is mostly nocturnal and very hard to spot. Reintroductions are helping it make a comeback.

The tiny, brown-and-white sand martin is a common summer visitor to the UK, nesting in colonies on rivers, lakes and flooded gravel pits. It returns to Africa in winter.

As its name suggests, the house martin can be spotted nesting in the eaves of houses in our towns and villages. Its intricate mud nests take days to build and are often returned to and used in…

The great diving beetle is a large and voracious predator of ponds and slow-moving waterways. Blackish-green in colour, it can be spotted coming to the surface to replenish the air supply it…

Britain's largest 'diving beetle' is an impressive creature, though it's not easy to find.