Birds don't urinate, so all of their waste is excreted in their droppings. People have found interesting and unusual uses for bird droppings, or guano, over the years. Learn about uses of bird droppings in this video.
Learn about guano, the excrement of seabirds, which is such an important resource that it has even started wars.
Find out about research showing bird behavior may be far more sophisticated than previously believed.