Birds have been immortalized for centuries in poetry and song, but their beauty and grace can't always conceal one less-than-lovely aspect of their existence: their defecation. That white, sticky mess that falls from above, covering our cars and houses -- and sometimes our heads -- is particularly troublesome because it seems almost impossible to remove. But blame nature, not the birds. Unlike mammals, which get rid of solid and liquid wastes through different orifices, birds have only a cloaca -- a cavity that lies at the end of their digestive tract and is responsible for the excretion of all waste. So, because birds can't get rid of nitrogenous waste the way mammals do, they have to combine it with their feces and let it fall where it may. For what it's worth, the white part of the gooey discharge is the uric acid, and the dark part is the feces.
Fun facts about our feathered friends:
- Ostrich eyes are larger than their brains and are the largest eyes of any land animal.
- One reason why birds are capable of flight is because their bones are hollow, like straws.
- If they lack access to water, some birds will "bathe" in dirt or let ants climb on them to remove parasites.