Figure added for present website. Upright postures in various genera of muroid rodents: A) Clethrionomys (Johst, 1967). B) Dicrostonyx (Allin and Banks, 1968). C) Rattus (Grant and Mackintosh, 1963). D) Lemmus (Arvola et al, 1962). E) Microtus (Clarke, 1956). F) Mesocricetus (Grant and Mackintosh, 1963). G) Otomys (Davis, 1972). H) Peromyscus (Eisenberg, 1962). I) Mus (Grant and Mackintosh, 1963. In most cases the upright animals are apparently defensive, although in the following cases one animal appears to be offensive: the right Dicrostonyx, the left Rattus, the right Lemmus, the left Mus.