Sleeping on the ground!?

I enjoyed the movie for what it was, especially Brian Cox's narration. The minor problem I had with the main character was the scenes of him sleeping on the ground.

He's aware of the zombies/walkers/undead, so it seemed odd he would willingly sleep on the ground, leaving himself defenseless. I know, it is an easier scene to film, etc, but it didn't fit the story.

BOHICA America!