Pure gold...
"...male fruit flies, essentially, know when they've reached the optimal level of inebriation to attract more females and successfully mate, before they become so intoxicated that they repulse the females, or approach other males by mistake."
(Thought I'd have to read the article to find out if they're any more successful than we are, but thanks to aureliusm's comment, I won't. Too depressing, being beaten by those annoying little gnats.)