A sea otter “smiles” for the camera in Monterey Bay National Marine Sanctuary. Photo credit: Douglas Croft.

Sure, they’re otterly adorable, but there’s a lot more to sea otters than meets the eye. Here are some of our favorite fun facts about sea otters for Sea Otter Awareness Week:

• Sea otter fur is the densest of any mammal on earth. Just one square inch of their bodies can contain more than one million hair follicles! These hairs create a wetsuit-like layer of protection against the cold waters of the Pacific Ocean.

• Sea otter teeth are twice as strong as our human teeth! This helps them crunch through the tough shells of their favorite snacks, such as clams, urchins, and mussels.

• Sea otters are one of a few mammal species known to use tools to help them survive. They will hold objects, like rocks, in their paws and use them to smash open the shells of their prey.

• Sea otters have pouches of loose skin under their forearm and armpit areas that allow them to store food for later, or rocks that they can use to crack open hard shells.

• A group of sea otters resting together in the water is called a raft. To prevent drifting off with the currents or away from the group, otters will often link arms or hold on to kelp while they sleep.

• Sea otters have an incredibly high metabolism, in part to help them regulate their body temperature. To survive, they need to eat at least 25 percent of their body weight in food every day!

Photo credit: Douglas Croft