David found this caterpillar on the porch railing while we were outside earlier. Since it stuck out like a sore thumb there, I moved it to some vines growing in the yard to give it better camouflage. I left it there after photographing it.
I think it might be an Eastern Tiger Swallowtail caterpillar, though its small size makes me second guess my ID. Those caterpillars feed on black cherry trees which would explain why it was on the railing. It must have fallen from the leaves onto the porch.
After realizing this, I felt guilty for having moved it so far away from the tree to the vine, which was on the other side of the yard; so I went back outside after dark with a flashlight to search for this caterpillar. I found it very quickly, still on the vine, and moved it back into the leaves of the tree.
I find myself sitting here questioning why I would do that and whether or not others would do the same. I suppose my reasoning is simply that everything deserves a fighting chance, no matter how big or small. I doubt many people personify insects or other animals in the same way that I do, but my conscience nagged me into giving this caterpillar a better chance of survival.