A baby kangaroo peeks out from its mother's pouch at a German zoo on Oct. 14. Usually, female kangaroos give birth to one joey at a time. After birth, the joey crawls into its mother's pouch, where it will nurse and continue to grow and develop. Red kangaroo joeys do not leave the pouch for good until they are over 8 months old; gray joeys wait until they are almost a year old.