This mole is active throughout the year, both by day and by night. In winter it burrows through the snow or travels on the surface of the snow. The home range probably extends over about 0.4 ha. The star-nosed mole is an expert swimmer and diver. It uses all four feet in swimming and traveling under the ice in winter.
Considerable food is obtained on the bottom of ponds and streams.
The diet consists of aquatic insects, crustaceans, small fish, and earthworms. The star-nosed mole is often found in small colonies. Unlike the case with most moles, a male and a female may live together during the winter. The young become independent at about 3 weeks, when they are approximately two-thirds grown. Sexual maturity is attained at about 10 months.