(a) North American the bog lemming, Synaptomys borealis (obsolete rare); (b) English regional a shrew (genus Sorex) (now rare).

Any of various semiaquatic rodents, esp. of the family Cricetidae. North American. The muskrat, Ondatra zibethicus, of western North America, and…

the common lemming of Scandinavia, Lemmus lemmus, which is noted for its fluctuating populations and periodic mass migrations.

A genus of Rodentia, somewhat resembling the common mole.