|Sorex hoyi (Pygmy Shrew)|
Size: Total length: 2-4 inches, 67-98 mm
Tail length: 1-2 inches, 25-34 mmWeight: less than 1 pound, 2.2-6.6 grams 
Description: Slim skull with pointed face. Covered in soft fur, gray-brown in color with lighter underside.
Similar Species: The major distinguishing factor between Pygmy Shrews and other species of the same genus are the number of unicuspid teeth on the top jawline, 3, as opposed to four or five.
Range: Pygmy Shrews are permanent residents across much of North American, specifically in northern Canada, east-Central United States, and the large majority of Minnesota.
Habitat: Preferred habitats for the Pygmy Shrew seem to be northern forests, edges of tundrous regions, and in mountainous terrain. They may be found in both soft and hardwood forests, as well as burrowing within moist soils, pre-constructed tunnels, and other biotic litters.
Diet: Pygmy Shrews are omnivores, tending to lean more toward a carnivorous existence. Insects and small invertebrates make up much of their diet. Pygmy shrews eat constantly, as they are so small and have extremely high metabolic rates.
Activity: Very little is known about Pygmy Shrew activity, although controlled environment testing show a high level of feeding, climbing, and sleeping throughout the entire day, identifying more with a crepuscular mammal.
Reproduction: Pygmy shrews mate during the summer months, gestating for approximately 18 days. A typical litter holds between three and eight offspring. Little is known about post-birth maternal care, aside from the fact that offspring must nurse for some period of time. These offspring are ready to mate two years after birth.
Lifespan: Up to 2 years.
Notes: Smallest American mammal.
- Montana Field Guide, Pygmy shrew: sorex hoyi, http://fieldguide.mt.gov/detail_AMABA01250.aspx, retrieved September 23, 2012
- Long, Charles A. (1974), "Microsorex hoyi and microsorex thompsoni", Mammalian Species 33: 1-4
- University of Michigan, Pygmy shrew, http://www.biokids.umich.edu/critters/Sorex_hoyi/, retrieved September 23, 2012
- Saunders, D.A. (1988), Pygmy Shrew, http://www.esf.edu/aec/adks/mammals/pygmy_shrew.htm, retrieved September 23, 2012