As its name suggests, Himalayan balsam is from the Himalayas and was introduced here in 1839. It now an invasive weed of riverbanks and ditches, where it prevents native species from growing.

The wigeon is a colourful duck that can often be spotted wheeling round our winter skies in large flocks. A dabbling duck, it surface-feeds on plants and seeds in shallow waters.

The water vole is under serious threat from habitat loss and predation by the American mink. Found along our waterways, it is similar-looking to the brown rat, but with a blunt nose, small ears…

Their empty, delicate pink or yellow shells can often be found washed up on beaches, but the animals themselves live buried in the sand all around the coasts of the UK.

Have you ever seen those worm-like mounds on beaches? Those are a sign of lugworms! The worms themselves are very rarely seen except by fishermen who dig them up for bait.

The tiny, grey-brown house mouse is one of our most successful mammals. It thrives around buildings but is less likely to be found in our houses these days due to better construction.

A familiar garden bird, the great tit can be seen around bird tables and feeders, as well as in woodlands and parks. Listen out for its shrill song that sounds just like a bicycle pump being used…

The wall brown or 'wall' gets its name from the fact it rests on any bare surface or wall! It can be found in open, sunny places like sand dunes, old quarries, grasslands and railway…