The banana slug is often bright yellow, though it can be brown, white, and green ... are optical. Tiny black dots, or “eyes,” at the ends of the tentacles detect light and movement.

Incredibly, the UK is home to the largest land slug in the world – the ash-black slug. Despite its name, they come in all different colours, from toffee-blonde to brown and deep charcoal.

The yellow-brown slug, which lives under stones, gets its name from the lumpy shapes all over its body. Shoresearch is The Wildlife Trusts' national citizen science survey of the intertidal shore.