Credit: Unsplash/CC0 Public Domain

Every evening, as they move from place to place through the forest, chimpanzees stop to build a nest—most often in a tree—to sleep in. Using a selection of branches, leaves and twigs, they create comfortable and safe spaces to get some shuteye.

Like human beds, these are places to rest—but they also help chimps stay warm or cool and protect themselves against the weather. As you might expect, how and where chimpanzees build their nests depends on things like temperature, humidity, wind and rainfall.

But how do they make these choices?…