Two cows are grazing in a pasture enjoying their grass.

At around noon they decide to lay under a tree, chew their cud, and talk for awhile.

The first cow says to the other:
"Have you heard about that awful new Mad Cow Disease?"

The second cow, chewing her cud says:
"Yea, I heard about."

The first cow says:
"Well, I'm really worried! I heard that a lot of the cows in the pasture down the road have caught it!"

The second cow says:
"Yea I heard."

The first cow says:
"Well you don't seem to worried about it!"

The second cow says:
"I'm Not worried."

Irate now, the first cow says:
"How can you just lay there, and not worry about such a horrible Disease!?"

The second cow says:
"Easy, because I can't catch it"

The first cow says:
"And Just What Makes Think That!!!"

The second says:
"Because you stupid Cow, Can't you see? I'm a Duck !!!"