Full Idea
Animals of both sexes cease to have intercourse after impregnation; that shows how little animals value pleasure, and that nature is all that counts.
Gist of Idea
Animals don't value pleasure, as they cease sexual intercourse after impregnation
Source
Plutarch (64: Gryllus - on Rationality in Animals [c.85], 990d)
Book Reference
Plutarch: 'Essays', ed/tr. Waterfield,Robin [Penguin 1992], p.394
A Reaction
A famous monkey had an implant to stimulate pleasure, and a button to trigger it. It apparently would have starved to death rather than release the button. Animal sex is dull?