Frisky swimmers is a term used to describe two species of aquatic mammals, otters and sea otters. Otters are small, semi-aquatic mammals that have long, slim bodies and short legs. They are found in rivers, lakes, and coastal areas around the world. Sea otters are larger than their freshwater counterparts and are found in the northern Pacific Ocean. They are known for their playful behavior and are often seen swimming on their backs or floating on their stomachs. Both species are considered to be frisky swimmers due to their active and playful nature.