Red Velvet Mites. Don't kill them. They will attack and eat other insects in your yard. They are a beneficial insect, not chiggers which are much smaller and you cannot see them. Cool pics!
You definitely can't see chiggers. I would know...I made the mistake of walking through part of our yard the other day wearing shorts without bug spray. My legs are COVERED in bites. The backs of my knees are the worst!