Slugs have a really rough tongue they use to lick up the green waste you put in the compost bin.

THE COMPOSTING CREW

Here are just a few of the creatures that live inside a compost bin.
Sid the Slobbering Slug who sucks the last juices out of your apple cores and uses a rough tongue to lick the surface of vegetable scraps.
Clare the Clever Centipede scampers around the compost heap on her many legs, busy looking to insects and spiders to eat.
Mike and the Microbes are so small they can only be seen under a microscope. But, they are really busy in the compost bin, feeding on the green waste and making it rot down and turn into compost.
And of course there is Wendell and the other wigglers who can eat about half their body weight in food everyday.