Who Teaches Birds to Build Nests?

I found a bird's nest today on my early-morning walk with Elaine. It was on the sidewalk below a fence. I brought it home. It's amazing to me that birds can create something so amazing. A nest has to be planned in advance; they are complex. Just think about all the materials used to build a nest. Mud has to be gathered first to make mud for mortar. The mud is mixed with a bird's saliva and then formed into a nest shape. Grass, moss, feathers, etc have to be obtained and added. Birds are like civil engineers.