Strychnine (/ˈstrɪkniːn/ STRIK-neen or /-nɪn/ -⁠nin; US mainly /ˈstrɪknaɪn/ STRIK-nyne)[5][6] is a highly toxic, colorless, bitter, crystalline alkaloid used as a pesticide, particularly for killing small vertebrates such as birds and rodents. Strychnine, when inhaled, swallowed, or absorbed through the eyes or mouth, causes poisoning which results in muscular convulsions and eventually death through asphyxia.[7] While it has no known medicinal effects, in the past the convulsant effect was believed to be beneficial in small doses.