For worms, I ordered 1000 worms online from Uncle Jim's Worm Farm (Amazon.com) The reviews were excellent, and delivery was prompt. I added them to the bin and wondered within the first month or so, if many had possibly escaped. I couldn't find but a handful at first.
I was also concerned that maybe the red wigglers didn't like the Texas heat very much. The worm farm was enduring sweltering 100 degree days, in the shade beside the house.