I used to use a thousand or more night crawlers per season and they were kept in a frig just for it. They liked shallow bedding about three inch deep and cool temps about 50 degrees. Can't really raise those cause they take a very long time to reach maturity. Never tried keeping them in compost thou, don't know if it would work. There are some good books out their on it. They were picked in spring after heavy rain and could not be injured or they would die and ruin bedding and start a bad circle of stinky death.
Red wigglers are very easy, flow thru bins are nice, I have a fifty gallon drum in basement along with a rectangle bin for them too. They are great for panfish and trout.