There was a largish beaker on the desk at the front of Somerset High's biology classroom. It was filled with a nasty-looking liquid... liquid which had settled in a couple of brownish layers.
There were small round bodies circulating through the fluid.
It looked pretty revolting.
Mr. Rhodes looked on contentedly as the class filed in, many of the students making "ew yuck" noises.
"What is that?" someone finally asked.
Mr. Rhodes explained that, in a world facing the realities of an ever-growing number of humans to feed, it was important to investigate unconventional sources of nutrition, especially protein. Among these potential food sources were these critters which thrived in many climates, in... uh... a renewable resource.
"They're called sewer lice," Mr. Rhodes continued, matter-of-factly.
There were general noises of disgust all around. It gradually sank in... Mr. Rhodes was just crazy enough to do it, wasn't he?
He was. He reached into the beaker and popped one of the swimming critters into his mouth.
He then taught the lecture, without ever again elaborating on the subject.
I wasn't about to blow his cover, but I had the unfair advantage of knowing that the liquid was a mixture of ginger ale and cola, the "lice" were raisins, and Robert Rhodes was master of deadpan humor.