8. Monkeys pay for sex
Christophe Simon / AFP / Getty
A study published in Animal Behavior found that male long-tailed macaques in Indonesia traded grooming services for sex with females. The boys even paid upfront. And the lady macaques? Well, they held up their end of the deal, too. Female sexual activity more than doubled — from an average of 1.5 times an hour to 3.5 times — after a good grooming. The researchers also noted that the going rate, i.e., the amount of time males spent nit-picking, dwindled as the number of available females went up.
Twilight Sequel New Moon Sets Records at the Box Office
Climate Central: Training Pilots to Land on Skis
Who Will Inherit Joel Stein's Kid?
Cartoons of the Week
The Weekly Acoustic News
Asterix at 50: The Comic Hero Conquers the World
Silvio Berlusconi and the Politics of Sex
Pictures of the Week
Short List: TIME's Weekly Critics' Picks
Piecing Together Nabokov's Last Novel