Background: I was telling my students they can't add "x" and "x squared" together because they're not like terms. I used the example that I can't add up my scrambled eggs and all my chickens to say that I then have more chickens then I did before (even though the eggs that I scramble do come from chickens originally). After the students on their own discussed chickens, eggs, and the like, a student seriously asked:
"Are chickens reptiles?"
~M.E. (Period 4)