Yawning is contagious in both chimpanzees and humans, a possible proof that both are empathic being. Yawning is a reflexive-instinctive behavior that seems to be characteristic of all vertebrates. Yet its causes and purposes have not yet been completely identified. In addition to solely physiological causes, communicative purposes may play an important role, too. Within the context of the exhibition "Zzzz", large-format photographs of yawning humans and non-human primates are attached to window-panes at the MPI-EVA's Wolfgang Koehler Primate Research Center ("Pongoland") at the Zoo Leipzig. This exhibition is part of a larger exhibition called "buchstäblich" (engl. "literally") that takes place from March 21 to April 28, 2019.