River otters are members of the weasel family, and are equally comfortable on land or in the water.

They probably are the most fun mammal Maine has, just because they like to play. But their play antics have a more serious purpose too. They teach their young survival skills, and hone their own, that way.

You will see them slide down riverbanks and muddy or snowy hills, wrestle with each other, bellyflop, somersault or juggle rocks while lying on their backs, according to the Smithsonian’s National Zoo and Conservation Biology Institute.

The otters in this video courtesy of Colin Chase have found a fun log to include in their games.

Otters are social creatures but usually live alone in pairs. Parents raise two or three kits that are born in spring in a den near a river or stream, the Maine Department of Inland Fisheries and Wildlife website says.

They primarily eat fish, but also shellfish, crayfish and sometimes turtles, snakes, muskrats and small beavers, according to the MDIF&W.

Otters can swim up to a quarter mile under water, and their noses and ears close while they are submerged. They also have a membrane that closes over their eyes so they can see better under water, the Smithsonian said.

They are mostly nocturnal so it’s a treat to see them during the day, playing or hunting for food.