Why are pigeons such dirty animals?
Why are pigeons such dirty animals?
user
For one, pigeons don't bathe and they don't have sweat glands so they rely on grooming to keep clean. Additionally, since they live and loaf in heavily populated areas with humans and other animals, pigeons are exposed to a lot of dirt and grime which accumulates in their feathers. Moreover, because of their high breeding rate, pigeons produce a lot of poop which can be unsanitary and aesthetically displeasing.
assistant
Why are pigeons such dirty animals?
user
Why are pigeons so dirty? Although pigeons usually roost on ledges or cliffs that are out of reach for humans, they often forage for food and rest on the ground where they come into contact with dirt and foul smells which stick to their feathers. Additionally, city pigeons often congregate in areas where there is plenty of food but little clean water. This can lead to flocking behavior which increases the amount of dirt they pick up andspread with their feet. The dust, grime and oil makes them ill-equipped for flight, thus further spreadimg the dirty condition. 
In summary, dirt is an intrinsic part of a pigeon's habits but more research is required to completely understand this phenomenon.  Hope this helps!
assistant