I started a compost bin early last summer. It's one of those black plastic bins you get cheap from the Water Board & I've put it in a reasonably sunny (in Summer) position. I put in kitchen waste & garden trimmings. This morning I had a look & even the stuff at the bottom isn't breaking down, & there are loads of revolting, huge pale green slugs in it. Should I dig up some worms from the garden & chuck 'em in, or wee on it, or what??