Deer have horrible vision -20/40 vision, in fact! For this reason, deer rely more on their sense of smell and hearing. Because deer vision is so bad, Deerbusters recommends adding white warning banners to the deer fence. These warning banners for deer fences allow deer to better see what is in front of them, preventing the whitetails from potentially running into the fence and causing deer damage to your garden. We recommend that you tie one white warning banner on the fence for every 10 feet at a height of 4 feet. Avoid adding warning banners to the top of the fence -this allows the deer to gauge how high they need to jump to get to your garden. Deer warning banners come 50 to a pack, at 1 inch x 24 inches.