The Labrador Retriever has been the most popular dog breed in the U.S. for nearly 30 years. Sea lions and humans are the only two known mammals that can sync to a beat. About 3 percent of the ice in Antarctica is actually frozen penguin urine. A shrimp's heart is located in its head. Abraham Lincoln loved cats. He kept four at the White House, and his wife Mary Todd described caring for cats as his favorite hobby. The proper way to mourne your cat's passing in ancient Egypt was to shave off your eyebrows.