blubber (BLUH-buhr) noun. thick layer of fat under the skin of marine mammals.

Blubber covers the entire body of animals such as seals, whales, manatees, and walruses—except for their fins, flippers, and flukes. Blubber an important part of a marine mammal’s anatomy. It stores energy, insulates heat, and increases buoyancy.

Blubber is different than most types of fat. Blubber is much thicker and contains many more blood vessels than the fat found in land animals, including humans. Blubber is so unique that many marine biologists don’t refer to blubber as fat at all. To them, blubber is a unique type of connective tissue between the animal’s skin and its internal organs.

Do this experiment—in your classroom or at home—to create a blubber mitten and feel the effects of blubber first-hand.

Have you seen any animals keeping warm this winter? Snap a photo and share it on the Great Nature Project. You can create an account and upload your photos directly to the Great Nature Project site. You can also browse the photo stream and check out the photos on a map. Join the Great Nature Project in documenting the world’s biodiversity.