In multi-pet households, cats are able to get along especially well with dogs if they’re introduced when the cat is under 6 months old and the dog is under one year old. In homes with more than one cat, it is best to have cats of the opposite sex. They tend to be better housemates. Source: AnimalPlanet
A female polar bear typically gives birth to twins, though singles and triplets have been recorded. At birth, a cub weighs only 1.3 pounds (about half a kilogram), but they grow very quickly. Cubs depend on their mothers for warmth and fattening milk, which is 36 percent fat, according to the San Diego Zoo. LiveScience