"He stands swaying, his actions only slightly interrupted by the amputation of half his head."

Writes Gordon Grice in "The Red Hourglass: Lives of the Predators."

Then, while she is still eating, he crawls onto her back. He seems in this semiheadless state to have found a renewed vigor and sense of purpose. There will be no more showy stunts. His pale penis emerges from the rear of his body, extruded between the plates of his exoskeleton. His abdomen snakes around beside hers and forms a painful-looking curve. They begin to copulate.

Mantis sex. That description! Whew! It goes on...

Turning her face almost 180 degrees, she regards him for a moment, as if his attentions were a distasteful surprise. Then, twisting with some difficulty, she brings her raptorial forelimbs into position and strikes again. This time she retrieves the remainder of his head and a scrap of his thorax, from which one foreleg dangles.

He doesn't seem to mind.

He doesn't seem to mind! Ha. Well, try minding something when you have no mind. Anyway, there's quite a bit more, and the main idea is that the male insect's sexual performance is improved by the absence of a head: "He performs with more gusto once he's decapitated." Apparently, the brain is a source of inhibition.

I have exclamation points in the margin in this passage of the book, which I read a dozen years ago (when I went through a period of intense fascination with the essay form). I just got the book down from the shelf to answer a question over on Ask MetaFilter: "Can you please recommend good books (fiction or nonfiction) or websites about insects and/or spiders..? Not so much identification books, but ones about how they live, interact, etc." It was fun reading that again. I should leaf through other old books of mine and pluck out passages with exclamatory marginalia.