By autumn, they are nearly adult size. They may remain with their mother until she is ready to bear another litter. Curious and playful, otters romp and wrestle with each other or play by themselves, even as adults. On snow, they take three or four running steps, launch themselves and slide on their bellies. A scream is the danger call.
Otters are mainly nocturnal but occasionally venture out during the day.
Otter predation isn't common as few of our predators can catch an otter and females go to great lengths to protect their young. Too swift and agile to be caught in the water, otters are able fighters if cornered on land. They have tremendous strength, reflexes and endurance, sturdy teeth and powerful muscles. Otters do not store food for winter, nor do they hibernate. In winter, they spend much time in the water, which is often warmer than the air.