They are going into a series of tunnels that runs all through the town. Like I said before, the guy who made these tunnels was supposed to be the dead guy in the cave, but it doesn’t really matter if it is or not. It isn’t shown how many of the houses are connected by these tunnels, but they have been there for a while, before the current residents moved in. I guess because the houses are the same color as the occupants they just repaint them when they move to a new place.