They are "sexcellent". That is a pun for you, you will find lots of puns on the internet! Also: blonde jokes. - Ryan North

Good luck distinguishing which sign is the REAL sign when my entire front lawn is covered with thousands of little green signs - each with a different number! Ahahahah! I'll be EVERY address in the whole freakin' township! And what are you gonna do about it? Hopefully, NOTHING!

I'm totally applying assumed Creative Commons rights.

I speculate that the genesis of the chicken-joke lies in some situation such as the one illustrated above, but over time the original context of the joke was lost, which left the chicken sadly decontextualized.