I Am Legend- spoilers?

Inspired by mommain's question: "I thought the scene where he got caught in the zombie's trap was great, but very scary but I'm confused on how it was set up....I can't remember the exact words but he was talking earlier in the movie about the infected having lost all human instincts or whatever, so how were they able to set a trap?"

As others mentioned in her question- that assumption (on Will's part) was wrong. I thought, at first, it was a matter of mimicking behavior until I saw the fight between Sam and the Dark Seeker dogs.
Did anyone else notice the head Dark Seeker was holding them back? It looked, to me, like they were pets or hunting dogs (much like Sam was to Will)??

Will stated they have lost human tendencies but I think that was before he met the alpha male, who obviously still exhibited human traits. I think the trap was set up by him honestly. I think that it was another way of showing how he was teetering on the edge of sanity and forgot he set up the trap himself, because it was just like the trap he set up to get the female darkseeker. Or maybe the alpha male copied the trap Will made, because he was definitely "smarter" or more developed than the other darkseekers.

Yes, the alpha male was holding the mutated dogs like pets before he released them and they had to wait for te light to pass, another example of human behavior.