Ah...my wonderful otters once again

Sea otters have the thickest fur of any mammal. A sea otter’s fur is an evolutionary marvel. Within just one square inch, otter fur contains 850,000 to 1 million hairs, making it denser than any other mammal on land or in the sea. The aptly-named fur seal comes in a distant second, with only about 300,000 hairs per square inch. Humans, meanwhile, only have about 80,000 to 120,000 hairs on our heads (if we’re lucky).