Not particularly dangerous but any animal can be if cornered and as others mentioned, they are possible rabies carriers. They are nocturnal so you wouldn't see them too often. When I lived in Missouri the only time I really saw them was the ones that got hit by cars at night in the road. I've never seen any in MN, I think they like warmer climates. Peej, you leave that opossum alone now, no tangling with the wildlife!