Why the tip of the eaves of the ancient houses upward

This is called a scops owl (chi), the dragon was born nine sons, among them it. "The last son chi dragon (chī), also known as the scops owl or chi (chī), fish-shaped dragon (also said to be like a lizard with a clipped tail), like to look around, so it is located at both ends of the ridge of the temple. In the scriptures, chi dragon is the rain god under the seat of the thing, able to extinguish the fire. So it is placed on the ridge at both ends of the roof also has the effect of extinguishing disasters and fires." I think there is also the role of light, lightning.