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'.

Living up to its name, the bullhead has a characteristically large, flattened head and a tapering body. Look out for it in fast-flowing, stony rivers and streams.

The green hairstreak is the UK's only green butterfly. Look out for the vibrant, metallic sheen of the undersides of its wings on grassland and moorland, and along woodland rides.

This tiny gamebird is rarely seen, but its distinctive "wet my lips" call can be heard ringing out over areas of farmland on summer evenings.

Look out for this tiny crab under rocks and boulders on rocky shores - you'll have to look closely though, they're pretty well camouflaged!

A small and delicate plant of chalk grasslands, Fairy flax can be seen in bloom from May to September - look out for its nodding, white flowers.

The alder fly is a blackish invertebrate, with delicately veined wings that it folds over its body like a tent. It can be found near ponds and slow-flowing rivers; the larvae living in the silt at…

Although introduced by humans, the fallow deer has been here so long that it is considered naturalised. Look out for groups of white-spotted deer in woodland glades.