This red admiral seems to be infested with something. My best guess is mites.
I think there is one on the right leg in front, and two on the back left leg.
They could be parasitic or predatory, but they might just be attached as a way of dispersing.
Mites are known to attach to other insects. The bumps on the bottom of this fragile forktail are mites. In this case, the mites use the damselfly to disperse from one body of water to another.
Other creatures use insects to disperse as well. This pseudoscorpion is just hitching a ride.
At a bioblitz I attended some time ago, people blacklighting for insects reported a snail attached to an insect. I would be interested to know if that was a coincidence or if snails do disperse that way.
This extremely uncomfortable bordered patch is probably the victim of attempted predation, rather than hitchhiking. I don’t think the spider was large enough to kill this butterfly, but I am not sure. The butterfly is obviously very uncomfortable.
Photos were mostly from my back yard, except for the bordered patch which was photographed in Texas.
The roused bear 
Amazing images and fascinating info, thank you.