Far and away your biggest potential hazard is poison ivy, which can cause a nasty rash depending on how allergic you are to it. It's everywhere, learn to recognize and avoid it. Birds spread its seeds and it thrives in our man-made landscape.

Unfortunately there's several other forms of local ivy that can be mistaken for it, particularly juvenile Boston ivy. The saying goes "leaves of three, let it be", but Poison Ivy's middle leaflet has an extended stem on it and Boston Ivy's doesn't.