Since 1532 according to https://wonderclub.com/Wildlife/mammals/norwegian_lemming.html https://wonderclub.com/Wildlife/mammals/norwegian_lemming.ht... Lemming

Since 1532 according to https://wonderclub.com/Wildlife/mammals/norwegian_lemming.html https://wonderclub.com/Wildlife/mammals/norwegian_lemming.ht... Lemming suicide is also mentioned on page 66 of the first edition of Confessions of an English Opium Eater by Thomas de Quincey: https://archive.org/stream/confessionsofeng00dequ_1#page/66/mode/2up/search/leeming https://archive.org/stream/confessionsofeng00dequ_1#page/66/... This was published in 1832 and revised in 1856.