We have 2 on the go at our school, and the cookery students chuck their veggie and fruit peelings onto it every day. The school restaurant give us the salad leftovers, the offices give the contents of their paper shredding machines, and the woodwork department have given us "some" of their vast quantities of sawdust. Added to this are the lawn cuttings from our garden club lawn, the weeds and prunings and we have a great pile. Aparently, according to Bob Flowerdew, urine is a great accelerant for your compost heap so, occasionally under cover of weekend gardening, I get my small son to help out in that area! All together, with very little mixing due to lack of time on my part, I have the most wonderful pile of stuff, full of worms, fruit flies, slugs, frogs, and any number of scavengers .... squirrels, robins, a rat occasionally ..... and they all add to the "ecosystem" you mentioned in your article. And, I too get those strange mottled grey/beige slugs!! I've never seen them before. Must be a compost heap thing!! Isn't life wonderful!!!!