Science and Medicine

Chimpanzee holding baby. Researchers have reported some of the first evidence that chimpanzee youngsters in the wild may tend to play differently depending on their sex, just as human children around the world do. (Credit: iStockphoto/Gabriela Schaufelberger)

Researchers have reported some of the first evidence that chimpanzee youngsters in the wild may tend to play differently depending on their sex, just as human children around the world do.

Scientists at Harvard University and Bates College say female chimpanzees appear to treat sticks as dolls, carrying them around until they have offspring of their own. Young males engage in such behavior much less frequently.

The new work by Sonya M. Kahlenberg and Richard W. Wrangham, described this week in the journal Current Biology, provides the first suggestive evidence of a wild nonhuman species playing with rudimentary dolls, as well as the first known sex difference in a wild animal’s choice of playthings.

The two researchers say their work adds to a growing body of evidence that human children are probably born with their own ideas of how they want to behave, rather than simply mirroring other girls who play with dolls and boys who play with trucks. Doll play among humans could have its origins in object-carrying by earlier apes, they say, suggesting that toy selection is probably not due entirely to socialization.

Read more: Young Female Chimpanzees Treat Sticks as Dolls

“I think it’s important to not scare people, but to teach them how to clean up and make sure they keep their play area safe. It’s most dangerous for toddlers or kids who are putting things in their mouths,” Page said.

Raccoons create latrines, particular locations they visit repeatedly. While this practice may be sanitary for the animals, humans—particularly small children prone to putting strange objects in their mouths—can contract a deadly, parasitic roundworm when they encounter these animal outhouses.

However, recent research may have struck upon a prevention strategy. The study found that sterilizing these latrines and leaving out medicated bait for the raccoons—as is done to control rabies—can reduce the presence of the parasite.

There are only 18 known cases when the worm, Baylisascaris procyonis, has infected humans, and all occurred in North America. However, infection doesn’t become obvious until the worm’s larvae move into a victim’s eyes or central nervous system, where they cause blindness, permanent neurological damage, or death. As a result, it’s possible cases have escaped detection, according to Kristen Page, a disease ecologist at Wheaton College in Illinois and the lead author of a paper published in the January issue of the journal Emerging Infectious Diseases.

There are multiple ideas as to why raccoons create latrines, which multiple animals use to defecate repeatedly, including as a means of communication or sanitation, she said.

Read more: Raccoon Toilets Sanitary for Critters, Deadly for Humans