Histerid-riding mites might resort to a leg clamp in order to hang onto their beetle as it dashes about and tries to fly. I've seen this behavior several times with histerids and I think I've also noted it with small dung beetles. This one remained clamped to this beetle's right hind leg throughout the photo shoot. The image is grainy due to my boosting the ISO to freeze motion as the histerids were constantly in rapid motion.