I've tried a lot of different worm bins. Most of them didn't work. All the small plastic kind didn't have enough volume to keep up with our scraps, and had temp/moisture fluctuations that were bad for the worms. Some of the tower kinds were almost impossible to harvest from.
So I built something like a large wooden cold frame, filled it with bedding, and put window screen over it to keep out flies. I put hardware cloth in the bottom to keep mice out, but keep a connection to the ground; that way moisture would be regulated and the worms could burrow down to hide from weather extremes.
So far, so good . . . except that mice are getting in through cracks where the wood warped and raccoons have figured out how to pull off the screen on top.
What are you all using? And how long have you used it for?
Hi Gilbert, we love our worms and compost bins.
It may be worth to replace the wood and add a latch lock so the critters can't get in as easily. If the weather is dry, one could add a little hot pepper powder where the mice are digging. It would make the mice sneeze whilst digging and hopefully retrain them to leave your worms alone.
I too have found the small plastic stackable worm bins to be too shallow. Here are a few photos of our bins. It's good to have space within a bin to rotate the worms feeding. Putting food in the same place can cause that part of the bin to become really acidic. Add a little brown material to keep the pH balanced.
You could use the HDX Tough storage bin, the largest is 55 gal and costs less than US $20 when on sale from Home Depot. They are much stronger than Rubbermaid. With careful feeding you won't need drainage at the bottom. Just drill holes in the lid for air.