Ever wonder why fence contractors add those white flags to deer fence? They aren't just any fence accessory. 

White deer flags are added to deer fence to alert whitetails that a structure is coming up fast. This is helpful for when deer are running, potentially away from a predatory animal, and are about to hit the fence head-on. 

The white color is used to symbolize a deer's tail. When deer sense alarm, their white tails stand up to alert other deer of danger. The color also stands out to deer, as they cannot see the black color of the fence mesh.

Deer have poor vision, 20/100 in the daytime; and the white warning banners help deer see what is in front of them before colliding with the structure.