Visitors to the wild animal park in Shenzhen, China, last spring saw a smartly dressed rhesus monkey pick lice from the feathers of a parrot. Turns out, the 10 kilogram (22 pound) primate is an expert groomer. It has opposable thumbs that can be placed opposite of the fingers, giving the monkey a good grasp of the tiny parasites nestling in the bird's feathers. In the wild, female rhesus monkeys groom other females, their infants. and possible mates Besides keeping the family clean, grooming strengthens the monkey's social bonds. So this monkey and the parrot must be pals.