Smoky shrews may be active at all hours. They burrow through the leaf mold or travel in other animals' tunnels. They eat insects, salamanders, snails, worms, spiders and small birds either alive or as carrion. These shrews build baseball-sized nests of dry vegetation deep within rocky crevices or stone piles, or under rotting logs, stumps or boards. They breed from late March into August.
Offspring are independent by one month of age.
Smoky shrews appear to be social animals, with populations fluctuating from year to year. They fall prey to short-tailed shrews, weasels, foxes, bobcats, hawks and owls. Maximum lifespan is about 17 months. The long-tailed shrew inhabits the Appalachian Mountains from Maine to North Carolina. It occurs throughout Pennsylvania, except in the extreme southeast and west.