This sign warns people to avoid catching vomit from the feral chihuahuas that populate the desert. As the graphic shows, the chihuahuas levitate to the height of your outstretched palm then suddenly vomit. You never know what they’ve just eaten, so you are cautioned against catching it. I am always surprised to find signs that warn against things I wouldn’t do anyway.
It gives you a nice safe feeling that our government cares so much for our welfare.