another thing that works is horse manure, we had horses for ten years and the poop makes great worm bed material. We had night crawlers the size of Kindergartners pencil.
If you find a shady spot in the yard, dump cooled used cooking oil there. The red wigglers will draw to it. Keep it covered with something so the birds cant find them.
Thats what I have done and it works well.
Rookie Hog hunter, Advanced Bass fisher, Pro crap talker.