Although this is the smallest American mammal, it is by no means the smallest mammal in the world. The white-toothed shrews living in the so-called Old World - Europe, Africa and Asia - are almost half the weight of this species, and the hog-nosed bat of Thailand is equally small, at about half the weight of a penny coin or a dime.
Because of its small size, the pygmy shrew is able to occupy a range of microhabitats, such as moss, rotting stumps and the burrows of larger animals. It can even travel in the tunnels of large beetles. The coat of the pygmy shrew varies from grey-brown in winter to grey in summer; the underparts are light grey.
Pygmy shrews occupy a wide range of habitats, but they are sparsely distributed and often hard to locate. They feed on small invertebrates such as ants and spiders, and will also eat carrion if the opportunity arises. These tiny creatures live life at a feverish pace. Pygmy shrews forage in short bursts of just a few minutes and then rest for a similar amount of time. They nose through soil and leaf litter in search of prey, and often venture into the tunnels of larger animals to look for food. When threatened, pygmy shrews release a musky odour from glands on their sides. This smell not only deters the attacker, but also alerts any shrews nearby to the potential danger.
Distribution: From Alaska and eastern Canada to the Rockies and Appalachian Mountains in the United States.
Habitat: Forest, swamp and grassland.
Size: 5 - 6 cm (2 - 2.5 in); 2 - 4 g (0.1 oz).
Maturity: 1.5 years.
Breeding: One litter of about 5 young born in summer, about 18 days after mating.
Life span: Unknown.