I have two of those black plastic compost bins, which I use in rotation. Usually, when I start the new bin, it's not long before I notice lots of bugs and worms doing their work. However, although one of my bins is choc full of worms and bugs, the one currently in use does not seem to have any, even though it's almost full. I have checked for tunneling around the bin, in case there may be a rat under there, but cannot see anything. I compost all the usual stuff, tea bags, coffee grounds, cardboard tubes, vegetable peelings, plant & grass waste,& occasional newspaper. I do make sure also, that it is not too wet or dry. Please can anyone offer an explanation as to why this particular load is not attracting the usual 'workers'?