A scientific vulture, flying north for the summer, decided to take an airplane instead of doing it himself. His experiments indicated that while airplanes use far more carbon calories than vultures; they use far fewer vulture-calories.
Knowing that they don’t serve vulture food on airplanes, the vulture brought with him a dead armadillo to snack on.
The ticket clerk asked, “Do you want me to check that for you?”
“No need,” said the vulture, “it’s carrion.”