Wombats live alone but meet up to breed in April to June on mainland Australia. In Tasmania the breeding can occur at any time of the year. The young wombats are tiny, about two cm long, when they are born after a gestation of only 21 days, and move into the mother's pouch. Wombats normally only have one baby although the pouch has two nipples. Unlike a kangaroo, the pouch opens backwards, which would prevent it from filling with dirt as it crawls into its burrow. The young wombat lives in the pouch for about six months, and finally becomes independent of the mother at about 18 months of age. Wombats live for about five years, although some in captivity have lived for 26 years.