One irritating habit i’ve noticed of zombies is that if one zombie hits a vehicle it will then respond to the noise it made and keep on hitting the vechile until 90% of the entire thing is completely scrapped, right down to even the framework. This is even more frustrating when that sound attracts even more zombies to start a gang bang on said truck which can strip even a car down to a skeleton in a matter of hours.
Now maybe this is intentional and the zombies are trying to destroy vehicles to cut off their prey’s escape routes, but considering they don’t know how door handles work, I don’t think they have the higher brain functions for such tactics.
In short I think the AI should be fixed so that zombies don’t react to sounds they themselves made similar to how they ignore others footsteps.