I think we're thinking of roundworms in different ways. Seeing as they are a very diverse phylum of 25,000 different species that can be free living or parasitic, beneficial or not beneficial. A number cause disease to humans but definitely not all of them, and in case I didn't say it before my roundworm was microscopic meaning you'd never see it with the naked eye if that helps. There was only 1 in my field of view but it doesn't mean there wasn't more in the feces (rabbit pellets) as a whole, even so it was nowhere near harmful enough to warrant a deworming.