When I left the village, I didn't have anyone set to breed. When I returned the next morning, I had 15 mommas carrying babies. When the children turned two and I could see who the dads were, I found that one villager (the weird looking bald dude) was the dad of all 15! And he had since disappeared! He was not elderly or sick the day before, there was plenty of food and the fire still going, and everyone else was healthy, so no reason I could see for his death.