of macaque monkeys 'pay' for sex

Macaque monkeys 'pay' for sex: Michael Gumert from the Department of Psychology in Nanyang Technological University has done a research on 50 long-tailed macaques in Kalimantan Tengah, Indonesia, over a 20-month period and he found there was an increase in sexual activity after bouts of male-to-female grooming. On average, females had sex 1.5 times per hour, but immediately after being groomed by a male partner, this rate jumped to 3.5 times per hour.

[via neatorama]