Have you noticed this?

[Dyehardjr]

I think the zombies are learning.

Yes, some of them start out smart, like the marked one and the ones who can talk. But I think the others are capable of learning, at least to some degree. For example, in the army base the zombies know that Angel can't see them. The jumper knows that they are in the other building. If you look at the first lot of zombies in teh army base the first time, they were really stupid. "We left the keys in the door". It just seems like, as the series progresses, the zombies are getting smarter.

Also, the leader may have been a zombie for a while. Remember in the first episode, they mention how the mental asylum is only about 10 miles away. That's a big distance but not when your as fast as they are. We know that a marked serial killer was put in the mental asylum because he was judged insane. What if he had already been a zombie? As far as I can remember, they never mention exactly how he killed the people.

That makes complete sense. The zombies could gain greater intellect the more they experience the world. We know that a good chunk of the human population was turned into 'them', and that means that there are a huge ammount left. And as the weakest ones die, the greater and stronger ones learn and live on. Natural selection in a way.

But another question that's been buggin' me is "how exactly did the zombies realize that they should create a hive"? When you think about it, the arena is a large place that many zombies can fit in, and it could also work as a defencive structure for many MANY survivors... but how did the zombies actually discover to 'mimic' humans, and create their own bases of operations? Could they all be that smart?