These are Polyphemus Moths, or Antheraea polyphemus. It is one of the more common silk moths in our area and is easily recognizable by its large eyespots on each hind wing. It is the second largest moth native to North America (Male 4-5 in., female 4-6), behind only the Cecropia Moth. Polyphemus Moths fly from June to August in our region. Its caterpillars feed on oak, willow, maple, and birch.