I was watching a squirrel in our yard gathering nesting material and wanted to ask a few questions about that. I never had squirrels for pets or anything so I am clueless!

I do a lot of sewing/spinning/knitting/etc. Would it be safe to leave some fiberfill or wool roving out for them to find and use for their nests? What about small scraps of fabric like flannel?

Thanks for any help you can give me!