[Dylflon]

Yeah, the basic idea behind zombie hordes (gets talked about in the comics) is that one zombie will notice something or hear a noise and start walking towards it. Other zombies see a zombie moving with purpose and will begin following it, under the assumption that the zombie knows where something devourable is. Then more zombies see a group of zombies and want in on whatever action that group involved in. By this point the original zombie has forgotten what had gotten it moving in the first place. There's just a whole bunch of zombies walking in one direction simply because that's what they're doing.

That's how you get a zombie herd.

I think the point of the helicopter was showing that something inconsequential and far away could totally screw a bunch of people over by inadvertently creating a zombie mob.

Also, Sean: that wasn't Hershel's daughter that got eaten, it was his neighbour Patricia.