The Fairweather Gardener - Compost Bin, the Cons

Compost is a constant concern here, I only have space for one plastic bin and a small woodpile. The bin retains moisture and gets cuttings, weeds, trimmings and kitchen scraps and houses plenty of little red worms but also tens of hundreds of big green slugs. 

Ok I haven't got close enough to actually count them but I take my life in my hands when I heave off the lid, struggling with the weight. I feel I have to feed them every day or they will emerge and devour the garden, which is quite small. 

Help!