The stray cat

This post is kind of in connection to Sara's about the turtle, but this is about a cat. 

A LONG way back in the book (page 57), when Casy and Tom were wandering around the abandoned Joad house, a cat was mentioned repeatedly. It lived around the house and watched the men build a fire and eat. While reading, I kept waiting for the cat to have some sort of significant interaction with the characters, or to have some point to the story (plot-wise). Neither of those happened though, so I assumed that it had some symbolic significance.

The only thing I could think of was maybe it just represented Muley, the neighbor that refused to leave his land. The cat was forced to scavenge food like Muley was being forced to do. "The gray cat came out of the barn shed and trotted miaowing toward the fire, but, nearly there, it turned and went directly to one of the little piles of rabbit entrails on the ground. It chewed and swallowed, and the entrails hung from its mouth" (68). It was willing to eat the discarded guts of the rabbit because it obviously didn't have any people around willing to give up their food to an animal.

Honestly, I think that comparison is kind of weak. I wonder if there are any other things the cat could symbolize that would make more sense.