Looks like a polyphemus moth. https://en.wikipedia.org/wiki/Antheraea_polyphemus

My approach would be to get a tube of silicone caulk that handles a decent range of temps and a length of hose that fits over the tip of the tube to reach under if the caulk won't reach on its own.

Save early. Save often. - My 6th grade computers class teacher.

I had to do the same with chrome. The past week was not enough, so I had to choose to clear all time.