Incidentally, re worm bins. I just emptied mine to get the worm castings. Since I don't have one of the fancy ones with different chambers, I just took all the stuff off the top, bedding, food, worms and all and dumped it into a big wastebasket, down to the layer where everything was solid.
Dug all that out, put some fresh bedding in the bin, dumped all the rest back in and covered with more fresh bedding (i.e. fall leaves). Turns out it was a good thing to do. All the stuff at the bottom being so packed down was pretty soggy-wet and getting a bit anaerobic/ fermenty. So now I have a bunch of worm castings and the worm bin is all nice and fresh and aerated. Happy worms!