It is said that the Pingpu Aborigines took great pains to protect their water sources from pollution. When Han Chinese arrived in Taiwan, they found they could frighten off Aborigines without a fight just by "putting dead dogs in the water and hanging dead cats from trees," because the Aborigines knew when they saw them that there was probably an epidemic coming.
有一個關於台灣先民平埔族的說法，平埔族通常選擇住在水邊，就近可以照顧水源，防止污染；而漢人要佔據平埔人土地，不需費一兵一卒，只要「死狗放水流，死貓吊樹頭」，平埔人自然就嚇得遷移他地，因為知道緊接著可能是無法遏阻的污染與疫病。