Large 3-4 in bag hanging on my porch
Thank you for your question to eXtension.
That appears to be a cocoon for some type of moth, but unfortunately, I cannot identify what species that would be. Are there any nut trees nearby, like hickory? Sometimes, by knowing what host trees are nearby, we can narrow down our search for likely caterpillars.
The reddish "fuzz" appears to be silk, which is sometimes given off by a caterpillar as it gets ready to form a cocoon, which is also made of silk.
The moth will not harm the house, so you might want to leave the cocoon there and try to get a photo of whatever hatches out next spring. Otherwise, use a broom to remove the cocoon and webbing.