Strychnine ( \ / ˈstrɪkniːn \ / ; also US \ / ˈstrɪknaɪn \ / or \ / ˈstrɪknɪn \ / ) is a highly toxic ( LD50 = 0.16 mg\/kg in rats , 1-2 mg\/kg orally in humans ) , colorless , bitter crystalline alkaloid used as a pesticide , particularly for killing small vertebrates such as birds and rodents .
It was used as a pesticide , for killing small vertebrates such as birds and rodents .