In case it matters. I'm on PS3 and when I first disovered a small village early on I think that I accidentally caused them all to die, at any rate they disappeared so later on I used creative mode to spawn four replacements at the original site then switched back to survival. Perhaps I'm just not patient enough but I've built more houses for a total of nine, surrounded them with a wall and lots of light. Every time I check these four are alive but it's been many game days and they've yet to multiply.