Under my husbands 4 foot baby chestnut tree that is a variety (hybrid) of the one America has lost due to disease there were two of these fellows enjoying lunch. Because the tree is so small we did have to move them somewhere else into the woods. Perhaps they wandered back as we did not check.
There were two and they were each about 3 inches long. I think it is the caterpillar of one of the moths.
"Polyphemus Moth Larva Larvae reach nearly four inches in length and appear "pushed together" from the ends, making it accordion-shaped. Larvae are fat, pale green, and sparsely covered with hair which are not harmful if touched. They feed on many trees and shrubs including oak, hickory, elm, maple, birch, apple, boxelder, cherry, chestnut, willow, ash, grape, pine, and members of the rose family. The larval period is 48 to 50 days long. In late summer or early fall, the larva spins a rounded, tough, parchment-like cocoon in the tree or shrub in which it has been feeding. It overwinters in this cocoon, and emerges the following spring or summer as a very beautiful adult moth.
A common giant silk moth, the male has a wingspan of nearly five inches and the antennae are large and feathery. The wing color is light brown with gray dusting on the forewing edges and vertical pink lines near the body. Each hindwing has a larger yellow eyespot in a field of dark blue to black. Small yellow eyespots occur in the center of the forewing."
This is a photo I got from an Ohio website..
Wish I would see this some evening.