NHPA/Photoshot
The chimps are up to something. A massive study has found that the majority of chimp populations are sometimes active at night but cannot tell us why.
Chimps’ nocturnal behaviours have barely been studied, says Maureen McCarthy of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. “Researchers in the field follow them from the time they get out of their nest in the morning to the time they nest around twilight hours,” she says.
“What happens between the time they nest in the evening and the following morning has largely been a mystery.” However, …