This small, white heron is an increasingly common sight in parts of the UK as it spreads north from continental Europe.

This slim fish is usually found on gravelly parts of the seabed, close to shore, but can turn up in rockpools.

The common octopus is a highly intelligent, active predator. It even has a secret weapon - special glands produce a venom that it uses to incapacitate its prey!

The Marsh helleborine is a beautiful orchid of fens, wet grassland and dune slacks. Growing in profusion in places, look for reddish stems and white-and-pink flowers.

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.

Ground-elder was likely introduced into the UK by the Romans and has since become naturalised. A medium-sized umbellifer, it is an invasive weed of shady places, gardens and roadsides.