Why can't birds see glass?

Birds often cannot see glass because their vision is adapted to detect movement and patterns in the natural environment, such as trees and open skies, rather than transparent surfaces. Glass reflects light and can blend in with the surroundings, making it difficult for birds to recognize it as a barrier. Additionally, some birds have a different visual spectrum, which may not register clear or reflective surfaces effectively. This lack of awareness can lead to collisions with Windows and other glass structures.