So I sit down in my chair this evening and hear this sound. At first I think it's the dog chewing a Nylabone on the wood floor behind my chair but when I look the dog is across the room from the sound. I go outside with a flashlight and see a squirrel that has chewed through or knocked a screen out of a birdblock vent hole and is now chewing from the inside to enlarge the hole. I planned on leaving tomorrow afternoon for a month so looking for quick and effective solutions. Any and all suggestions appreciated.