Davening (prayer) is almost always better inside a building where there are fewer distractions. It is considered more modest to daven away from the public view. The one exception to this is at the Kotel. Davening at the Kotel is spiritually more intense when you are outside, without a roof over your head. Although it is certainly advantageous, there might possibly be a slight disadvantage to davening outside even at the Kotel.
Mostly we see doves, pigeons, and sparrows, but sometimes crows visit the Old City, too. Again this morning a few young American yeshiva students ran over to me at the Kotel and asked, "Oy! Is there anything special you're supposed to do if a bird poops on you?" He held out his arm to show me what he was talking about.
I explained, "Bird poop doesn't have an offensive odor so really you don't have to do anything. You can just wash it off."
They asked, "Is there anything you are supposed to say?"
I said, "Yes. You say, Thank G-d cows don't fly."