A good compost heap will be literally crawling with "critters". Here on our area in the western U.S. a lot ranchers use composted corn (stalks and leaves but not the corn itself) for cattle feed. It's placed in a long (100') concrete lined trench about 5 feet deep and then covered with heavy black plastic. After a month or so you'd be amazed at what crawls out. The cattle love it though...
So... the more worms and bugs one has in a garden compost container, the healthier the compost is and a sure sign of the bacteria working to breakdown the organic material...