With about 1 million hairs per square inch (per 6 square cm), sea otters have more hair per square centimeter than humans do on their entire heads. Humans have an average of 100,000 hairs on their heads and an additional 5 million on their bodies, but sea otters can have as many as 800 million hairs. Their incredibly dense fur serves to keep the otters warm and dry, and it provides the otters with four times the insulation that fat or blubber would. If the fur becomes dirty or slicked with oil, however, its insulating ability is lost, which is why otters are so affected by pollution.
More talking points about otters:
- Although sea otters are the smallest marine mammals, they can grow to be as long as 5 feet (about 1.5 meters) and weigh as much as 70 pounds (about 30 kg).
- Sea otters are extremely sociable, and they often float together in groups of as many as 100 otters, called rafts.
- Sea otters are one of the animals that use tools the most. Not only do they use rocks to bash open shellfish, sea otters also wrap themselves in blankets of seaweed for extra insulation while they sleep.