I've noticed that there's quite a few small black and yellow caterpillars on my house. They're half an inch long or smaller and slightly fuzzy. I tried googling it and they do look a lot like Harrisina americana larvae, but according to what I found, that species isn't found in Colorado. I did find mention of Harrisina brillians which is in Colorado, but they caterpillars I have don't really look like the pictures I've found. Also I would think they would be on the grape plants if they were one of those species. I haven't seen any on the grapes at all or any plants. Just on the house itself.