Like all underwing moths, the bay underwing camouflages perfectly on the bark of a tree. When it flies, it flashes it’s bright orange underwing, which may startle a predator just enough to allow it to flit away, land on a nearby tree, and disappear. This is a medium-sized moth, with wings about an inch (or a bit more) across. It has a relatively small range. It can be found from southern Maine and New Hampshire to New York.