Do the villagers build their own houses?

I just got minecraft: pocket edition and I'm on creative mode. I spawned some villagers and built myself a house. I was wondering if the villagers build their own houses or do I have to build them for the villagers?

No, they spawn in villages that are rare but naturally spawning. You can look at this thread for what accounts for a house in the mind of villagers http://www.minecraftforum.net/...er-a-house. They do not build houses.

No, there generated when the map is created