The lesser horseshoe bat was once a cave-dweller, but now tends to roost in old buildings, such as stables and barns. It is rare in the UK and, like many other bats, declining in number.

This sponge is found on rocky shores around the UK and looks like a thick bready crust (if you use your imagination a bit!).

Fennel has feathery leaves and open, umbels of yellow flowers. It was probably introduced by the Romans for culinary use, and is now a naturalised species of verges, waste ground and sand dunes.…

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.

Cotoneaster was introduced to the UK in 1879 from Eastern Asia as an ornamental plant. It is now an invasive non-native species which is taking over valuable habitats including limestone…

The once-common pochard is now under threat because its populations are declining rapidly. The UK is an important winter destination for the pochard, with 48,000 birds visiting our wetlands and…