Adult chiggers don't bite. It's the babies, called larvae, that you have to watch out for. They're red, orange, yellow, or straw-colored, and no more than 0.3 millimeters long.
After they hatch from eggs, the babies don't fly and don't travel very far on their own. They tend to stay clumped together in large groups on leaves and grass, usually less than a foot off the ground, and attach to animals or people as they pass by.