Bears have anywhere from 1-5 cubs at a time, with 2 being the most common number. Most bears are capable of raising 2 cubs, with the exception of the Giant Panda. The Giant panda will often discard the weaker cub in favor of the stronger one, this is more common when the mother has a decreased milk supply or is a first-time mom. image: Pixabay.com 2. Bears have delayed implantation

Polar bear cubs learn to hunt by watching their mother. Cubs try hunting in their first year, but don't seem to be successful until they're over one year old. Even then, they only spend about 4% of their time hunting. By the time they're two years old they spend about 7% of their time hunting and can catch a seal every five or six days. Cubs who are born during hibernation spend the most vulnerable part of their life in the safety of their mother’s den. When they finally emerge in spring, the cubs weigh around 6lbs and many can already climb a tree. image: Pixabay.com 9. Polar bear cubs stay in their den for around 60 days Most dens consist of a single chamber slightly elevated from a short entrance tunnel, but they can be complex with several chambers. On average, the chamber is 2 m (6.6 ft.) long, 1.5 m (4.9 ft.) wide, and 1 m (3.3 ft.) high, not much bigger than the bear. Polar bears maintain a ventilation hole through the chamber ceiling to provide fresh air. At birth, polar bear cubs weigh about 454 to 680 g (16-24 oz.) and are about 30 cm (12 in.) long. Males are born slightly larger than females.Once mated, females begin depositing fat in preparation for cubbing. Females need to gain at least 200 kg (441 lb.) for a successful pregnancy. Polar bear cubs are vulnerable for the first few months of their lives. They are easy prey for predators like arctic foxes. Staying in their dens keeps them warm, and protects them from predators. When they leave they will be about 15lbs and more difficult prey for other arctic hunters. 10. Sunbear cubs are early foragers Because of the bears' body heat and snow insulation, the den stays warmer than the outside air temperature. Scientists are now using this heat to detect bears with forward-looking infrared technology (FLIR). The actual gestation length for bears is difficult to calculate. Bears can experience something called “embryonic diapause” or delayed implantation. This means that an egg is fertilized, and begins to develop into a blastocyst. The blastocyst will stop development until it implants in the uterine wall. It may be waiting for the bear to gain an appropriate amount of weight for gestation, or for an environmental factor to be just right. For this reason, a bear may technically be pregnant for 140 days but only actually gestate for 60. 3. Bears have very small babies

Cubs begin eating solid food as soon as their mother makes her first kill on the sea ice (about three to four months of age). The most frequent litter size is two, followed by litters of one. Litters of three are less common than twins or singles, and litters of four are rare. Most adult females give birth once every three years. In populations with access to abundant food, birth occurs once every two years. Grizzly bears cubs start eating solid foods at a few months old, but they will continue nursing for as long as 3 years. The mother bear will decide when she wants her cubs to stop nursing. This is usually when she is ready to mate again. image: Pixabay.com 6. Bears use trees as babysitters for their cubs For the next three or four months the cubs nurse as often as six times a day. The length and number of nursing bouts gradually decreases as the cubs grow older.Polar bear cubs are born November through January in a den. Mother and cubs emerge from their den in late March or April. Delayed implantation assures that the cub is born during the best time of the year for survival and allows the female to get into good physical condition and use her energy for nursing her newborn cubs. There are 8 species of bears in the world, with even more subspecies. The Brown bear alone has over 90 different subspecies. They differ wildly in the climate they prefer, their appearance, and their diets. From the immense Polar bear to the petite Sunbear bear bears show a variety of behaviors and appearances. One thing they all have in common is that they are endlessly fascinating, and have a reputation for being good mothers. What exactly do these “mama bears” have to put up with from their offspring? Keep reading for some cool facts about bear cubs. 10 cool facts about bear cubs 1. Most bears are born as multiples Mother polar bears are extremely protective of their young, even risking their own lives in their cubs' defense.