Villagers run toward Zombies when they are breaking doors.
When a Villager is in a house and it detects a Zombie breaking trhe door, the Villager will run to the door, get attacked by Zombie, and dies.
Reproduce:
1. Make house.
2. Put villager in it.
3. Spawn a Zombie.
4. Get it to break the door with a command if it can't already. (my friend told me it was this command: /entitydata