This small duck is an uncommon winter visitor to the UK, where they're usually found on lakes, reservoirs and gravel pits.

False widow spiders are often the subject of unflattering headlines, but in reality they're unlikely to bite humans.

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.

Barnacles are so common on our rocky shores that you've probably never really noticed them. They're the little grey bumps covering the rocks that hurt your feet when you're…