It's made for plants. Worms don't need that.
One thing I like to throw in my worm bins from time to time is organic wheat seeds from a health food store.
I soak them for up to 10 hours in cold water and scatter them on the surface of the worm bin soil. They grow
easily like lawn grass and after a week you have a jungle for the worms to play in. I use a pair of scissors to
trim the ends to feed them worms.
Here's a closeup with a Euro worm circled. The little white chips are crushed eggs shells.