it seems to me that the undead soldier zerglings can be incapacitated in battle, but not defeated/killed, as they can always be raised again by the WW king dudes. The only way to stop them/end them for good is to burn them?
When it comes down to it, the White Walkers are really just those 12 dudes--however many we saw in that scene with the baby. They basically have one primary magic--necromancy, and their army is whatever corpse they can roust up. I suppose this is one main reason it takes them so long to initiate an invasion. If the land north of the wall is desolate except for scattered wildlings, then it takes many years for that army to regenerate.
I'm also starting to think that due to the random nature of winter, it has more to do with the strength and desire of the White Walkers. Pretty clear those dudes created the ice and snow storm. I'm guessing that winter is a gauge of their current power whenever it happens. They don't always invade, because they don't always have the army to do it, but whatever is happening beyond those walls during the winter years must have something to do with their magic and actions.
The wildlings certainly know more about them, as they have lived with them for generations, and they were never a forgotten legend.
...so there are 12 or 10 of those WW Lords? How many houses are there in all of Westeros? :hmm: