Re: The Walking Dead Season 2 Discussion *Spoilers*
An alternative could be that they're instinctively or mnemonically drawn to food traps; ie. places where healthy people are likely to travel for medical supplies, food, water, transportation, fortifications, etc. That could explain the large zombie presence just off a main thoroughfare in Atlanta, roaming the freeway, surrounding the CDC and the FEMA aid center, and wandering way up to the reservoir and source of fish/game in the hills that was the group's former camp.
My name is Ozymandias, king of kings: Look on my works, ye Mighty, and despair!
Nothing beside remains. Round the decay
Of that colossal wreck, boundless and bare
The lone and level sands stretch far away.