Composting

I've been working on composting using another method besides trench composting for about two months now. I've enjoyed it so far, and been honestly trying to compost anything that is possible to compost. One thing I noticed though, as a moved from my brief time using a bucket (there were some holes), to a pile, is that I didn't see worms anymore. So I come to you composting experts to ask how can I bring more worms to my shady compost pile on clay soil.