If its too hot they will move to another part of the pile or leave completely. Why not start a worm bin?

Fito

they'll live in decomposing organic material happily, and prolly spread out if they breed lots, and if you bang a few around when you turn the pile ... oh well - think of all the bacteria and fungi you're disturbing when you turn the pile! when I turn my pile and come upon a bunch of them, always think of all the 'coitus interuptus' happening among friends, but they don't complain! :)

in your zone some will burrow down under the middle of the pile and gather to wait out winter, and many will pack it in, leaving cocoons behind to repopulate when the weather warms up - not necessary to purchase worms for a compost pile, but not really a waste of money either - as Fito sez, you could also start a worm bin in a sheltered location that might provide you a place to process kitchen waste thru the winter - try both!

Bill

Hmmm, I thought about throwing some worms into one of my leaf mould piles. It occurred to me though, that since they are just piles with no walls or top that wouldn't that be like Fuddruckers to animals that scrounge around for worms to eat? - Robin

I have a hole-in-the-ground "bin", I call my "field of dreams". (The theme being, build it and they will come). The bin is full of worms year-round. The fresh food keeps the temperatures up in winter and there is usually steam coming off it even in snow. In winter the worms are all around the edges and seem happy. Such a bin is at the mercy of the elements and predators but that has not seemed to make a difference as to the speed of composting. I do not really harvest compost from that bin as I just think of it as my organic garbage disposal. I have many other more confined covered bins for that. If I were buying worms, I would probably opt for making an enclosed bin and then maybe adding some to my outdoor pit to help populate a bit faster then waiting for them to just show up.