"The courtship chamber was placed on top of an identical chamber, with the chambers separated by muslin gauze," reports geneticist Yael Grosjean in a Methods section fit for a paperback romance. Then the "perfumed" portion of the experiment began. An aphrodisiac scent was presented on the other side of the muslin gauze. Scientists watched to see whether the subject, a male fruit fly, would be compelled to start courting his partner. To ensure that the female wouldn't influence the results with her responses, she had been recently frozen to death.
(This may seem unromantic, but keep in mind that in another part of the study, the females were headless. It didn't deter the males.)
A male fruit fly displays a scripted set of actions when courting a female, beginning with a buzzy sort of love song and ending with the deposition of his extraordinarily long sperm. Many animals use pheromones, ...
