Rats can be taught to play hide and seek -- and they squeal with joy when they win, scientists have found.
원문출처 : https://www.cnn.com/2019/09/13/europe/rats-hide-seek-intl-scli-scn/index.html
원문출처 : https://www.cnn.com/2019/09/13/europe/rats-hide-seek-intl-scli-scn/index.html