The Others - Lostpedia:
All of the Others left the Barracks for an unknown destination in December 2004. ok so it's unknown. I was trying to find out why they left, where they went. epis: Left Behind.
The Barracks site is currently intact but abandoned.
-The Others have since left the Barracks for another location.
-A group of Losties led by Locke is currently en route to the Barracks and intend to settle here, counting on their security system (i.e. sonic fence) to protect them from the seemingly threatening Freighter's people. ("The Beginning of the End" 4.1)

Unanswered questions
*Where did they live before moving to the Barracks? Why exactly did they leave this place?
*How do they call themselves? (they don't call themselves as 'Hostiles' or 'the Others')
*Why are the Others so unwilling to explain themselves openly to the Losties?
that's a good qstn. explain thmslvs, & what they know about the island - where it is, how they get to it, how they get supplies...
how and with whom they communicate...
*How did they acquire so rapidly precise informations on each survivor?
*How do they still get DHARMA-branded food?


Trivia
Lost producer Damon Lindelof said of the Others "...they eat chicken, they wear clothes out of the J. Crew catalog"
In Lost: The Complete Second Season (DVD), the Others' method of leaving no tracks was revealed when a group of 12 Others (the ones seen by Eko and Jin in "...And Found") are seen passing the screen, with the last member brushing off their trail with leaves.
Lost: The Complete Third Season (DVD) commentary reveals that The DHARMA purge was not the first purge by the Others. There have been many groups on the island, and the Others have purged many times before. Remnants of all the groups make up the Others we see today. Damon likens this to the United States, which is a nation of immigrants from many cultures who have assimilated into a common culture.


Pregnancy issues
The women among the Others suffer from degeneration of their reproductive systems. The condition was described as causing the reproductive system of a woman in her 20s to look like those of a woman in her 70s.
Juliet, a fertility researcher, was brought to the Island because she had discovered an effective treatment that allows women with damaged reproductive systems to become pregnant. On the island she began researching another condition where women's bodies had immune reaction against the fetus leading to the death of both early in pregnancy.
After the deaths of several volunteers among the Others, including Sabine, Juliet developed a theory that whatever went wrong in the pregnancy might be occurring at conception on the island. She asked Ben if she could take a woman off the Island as a control case to test the theory, but he refused to allow anyone to leave the Island. Claire, who arrived on the island pregnant conception occured off the islan, became their control case.

Juliet has gathered data on Sun's pregnancy. sad to learn that she conceived on the island so will have the attendant problems.