The slippery butterfish is a common sight in rockpools all around the UK. Look out for the distinctive black spots on their backs that look a lot like eyes!

An uncommon hedgerow and woodland tree of central and eastern England, purging buckthorn displays yellow-green flowers in spring, and poisonous, black berries in autumn.

A streaky brown bird, the reed bunting can be found in wetlands, reedbeds and on farmland across the UK. Males sport black heads and a white 'moustache'.

As the name suggests, the male blackcap has a black cap, while the female has a gingery one. Look for this distinctive warbler in woodland, parks and gardens.

A summer visitor, the wheatear is a handsome chat, with black cheeks, white eyestripes, a blue back and a pale orange chest. Look for it on upland heaths and moors.

Horsehair worms are parasitic worms of the clade Nematoida alongside their sister taxa Nematoda, the roundworms. The most famous trait of certain species of horsehair worms is the ability to alter…