It does seem like the villagers "know" what needs to be done, and they don't get serious about it until there's something pressing.
I have a game going where the population was recently at 13, so the builders got busy on the second hut -- then a couple of the older folks passed on, and now the builders think that hut is a complete waste of time

.
Kinda like watching the crops in the field sit unharvested because the bin is overflowing and the farmers would rather check out the cactus or the boulder!
-- jen