OK, I got an idea... I keep seeing these vermicomposters with different layers, looked at one and basically it consists of a tower with a screen on the bottom with a "compartment" underneath for the bed/droppings. Other than that it is food on top for them to eat. So... why not stack a couple of tires put a screen between the bottom 1 and 2. The bottom would have the bed and the top few tires would be for the food. Then when your ready to clean it or whatever you do you just take them apart. What do you think?