Kangaroos, like all marsupials have a very short pregnancy, 4-5 weeks. They give birth to underdeveloped young which are then cared for in the mother’s pouch until they are fully developed (several more months) and ready to venture out. Baby kangaroos, or joeys, once fully developed will spend more and more time out of the pouch, only returning to sleep or if there’s danger. They will return to the pouch for up to a year or until the next joey is born.