What better way to prevent birds from flying into windows than with natures own device? This static cling decal mimics a sticky spider web—a dangerous hazard that birds try to avoid. The zigzag area on a spider web is called a stabilimentum. Made in various patterns, they all do the same job. Scientists feel spiders use them to warn birds from flying into and destroying their webs. Placed on a window, this spider web decal has the same effect. Use two or more Warning Webs on large windows.