A medium-sized diving duck, the goldeneye can mainly be spotted in winter when birds fly in from Northern Europe. Conservation efforts have helped small numbers of these birds to nest in Scotland…

The pungent, rotten smell of Black Horehound makes this medium-sized plant of waste ground and roadside verges stand out from the crowd.

The unpleasant, astringent smell of Hedge woundwort makes this medium-sized plant of woodlands, hedgerows and roadside verges stand out from the crowd.

Pellitory-of-the-wall is a small to medium-sized herb that frequently grows from cracks in old stone walls, pavements, cliffs and banks, and churches and ruins.

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.

This brilliant red and white sea slug would make the perfect nudibranch for a Christmas card image or perhaps a football team mascot!

Turn over large stones or paving slabs in the garden and you are likely to find a red ant colony. This medium-sized ant can deliver a painful sting, so be careful! In summer, winged adults swarm…