[@Dark Light] They eat people. Like large cats they go hunting. It is possible for Daylighters and animals to pass into the Secret Hour through small tears or weak spots in the area the Secret Hour encompasses. Usually they just eat rabbits, deer, pets and livestock, but the occasional human gets through. Thousands of years ago Darklings used to be out all hours of the day and night hunting humans and eating them. But humans started getting smarter and finding ways to fight back. The Darklings created that 25th hour of the day in order to survive.