Only a few mammals -- humans and a few other primates -- are thought to spontaneously help one another.
원문출처 : https://www.cnn.com/2020/01/09/world/parrots-help-each-other-scn/index.html
원문출처 : https://www.cnn.com/2020/01/09/world/parrots-help-each-other-scn/index.html