Hummingbirds can't fly either........
At least according to the "science" of areodynamics. I quess we have to rely on empirical evidence here, right?
Keep in mind that cows produce copius amounts of methane gas and are thus, major contributors to green house effect.
I know, blame it on McDonalds. A world-wide boycott in favor of KFC is certainly in order. After all, how much methane could a few chickens produce?
Publius