Formosan rock macaques are a parent's worst nightmare: they don't finish their food, and they are far from potty-trained.

A researcher from the National Pingtung University of Science and Technology tells us why.

Many farmers that live near Kaohsiung's Shoushan view wild macaques as pesky animals because of their tendency to discard fruit after eating only a few bites. Macaques also spend most of their time foraging for food, and leave a trail of excrement wherever they go.

Su Hsiu-Hui of the National Pingtung University of Science and Technology has been studying the Formosan rock macaque species for over a decade at Yilan's Fu-Shan Botanical Garden. According to Su, the feces of these macaques help pollinate forest plants and also provide beetles with a source of nutrients. Reeves' muntjacs, which aren't able to climb trees, don't mind eating leftovers and also benefit from the eating habits of the wild macaques.

While these macaques that live near Shoushan have no fear of humans, even when nearby vendors aim BB guns at them, wild macaques tend to keep a distance from humans. They peacefully coexist with other forest animals and therefore play an extremely important role in maintaining the ecological balance in their habitat.