What are the little spiky orange and black bugs that crawl on my porch (western PA)?

Question

We have little bugs, about 1/2 inch long and like an elongated oval, that crawl all over our porch and I see them on trees. They are black with an orange stripe, and look like they are covered with spikes. I'd love to know what they are and what they do. We'd never seen them prior to moving to western PA.

Answer 1

Those are caterpillars that turn into the big orange butterflies....Those are a keeper...