Which of these animals has the densest fur of any mammal, with up to one million hairs per square inch?
Beaver
Sea otter
Polar bear
Arctic fox
Fact: The sea otter has the densest fur of any mammal, with as many as one million hairs per square inch in some areas of its body. Unlike whales, seals, and other marine mammals, sea otters have almost no insulating body fat, so they rely entirely on their incredibly thick fur to stay warm in the cold waters of the North Pacific. Their fur traps a layer of air next to the skin, creating a highly effective barrier against the frigid ocean. To maintain this vital layer of insulation, sea otters spend several hours each day meticulously grooming their fur.
Correct Answer: Sea otter