Iron Golems no longer actively seek out hostile mobs - they simply wander until they come across them, and even when they look at them will not do anything. Their attacks are also limited by blocks around them.

Put the summary of the bug you're having here

What I expected to happen was...:
The Iron Golem would attack the skeleton that was near the village

What actually happened was...:
It did nothing at first while the skeleton shot at it, until i pushed the skeleton over to it, where it then attack (but only when it was a few pixels away - less than a block length).

Steps to Reproduce:
1. Put into nighttime
2. Make Iron Golem
3. Watch as it does nothing to actively protect the villagers.