|"erosion control netting"|
Birds often try to make nests from pieces of the fabric, and get trapped in it. They starve to death! I'm not saying never to use it - just make sure it's installed properly, several inches beneath the surface, where it will never see daylight. If it's put on or near the surface, it inevitably will tear and shred, becoming a real eyesore and danger to birds.
What's commonly called "poison ivy" is not an ivy at all. All seven species are in the sumac family and are unrelated to ivies.
That's not a lot of comfort, however, when you itch like crazy. Of course, some people (I hate them, don't you!) aren't affected at all. Others have widely varying degrees of sensitivity.
You may come in contact with it unknowingly. So it's a good idea to aggressively wash your hands and arms (and other exposed parts of your body) with soap and water immediately after being outdoors.