Bee

Two men are walking down a street. One of them sniffs.
-What is it, what's wrong? - the other one asks.
-Well, I may be wrong, but it seems to me that it's two-propene-one-sulfinothioic acid S-two-propenyl ester and methanecarboxylic acid with a strong suggestion of one-propanecarboxylic acid; I'd wager it's one hell of a breakfast...
The second man looks astonished.
-My goodness me, man! You should have entered a smelling bee!

They disappear.