Over 200 million people live in Nigeria, which is almost twice as many people as the second-most populous African nation, Ethiopia. Barbie's real full name is Barbara Millicent Roberts. The record for having the most children goes to a Russian peasant woman in the 1700s. She had 69 children in 27 pregnancies, including four sets of quadruplets. The Guiness World Record for smallest dog is held by a 3.8 inch tall Chihuahua named Milly. When animals sleep through a cold period it's called hibernation, but when animals sleep through a hot period it's called estivation. Pope Gregory IX was apparently a dog person, because he tried to exterminate all cats from Europe.