Video: view
Slugs can be found on land and in the water, both freshwater and the sea. They are very similar to snails but slugs don't have a shell, and in fact any land mollusc without a shell can be called a slug. Since they have nowhere to hide inside and can dry out, slugs usually live in moist or wet places.
Someone is smug if they are very confident of their ability to do something, but at the same time are calm and complacent about it, as if they can do it very easily.
