(Self medicate, that is...)

It would appear domistication hasn't bred out all the smarts of your garden variety sheep:

In anecdotal reports, primates have been observed engaging in self-medication by selecting a specific plant when something has made them ill. Now biologists at Utah State University, Logan, have run experiments that show sheep choosing the right drug to cure an illness.

Seems like a "well DUH!!!" sort of experiment to me, but you never can tell what goofy result will lead you down a whole new path of discovery. Follow that sheep!