What does the last line, "Now what the hell ya suppose is eatin' them two guys?" tell us about Carlson?

Carlson is a laborer on the ranch where George and Lennie come to work. He is described in Chapter Two as a "powerful, big-stomached man." He is basically friendly and even makes a joke about Lennie's name, saying, "He ain't very small...Ain't small at all." In that chapter he also brings up the idea of killing Candy's dog because it's old and smells bad. When Candy balks at killing the dog himself in Chapter Three,...

Carlson is a laborer on the ranch where George and Lennie come to work. He is described in Chapter Two as a "powerful, big-stomached man." He is basically friendly and even makes a joke about Lennie's name, saying, "He ain't very small...Ain't small at all." In that chapter he also brings up the idea of killing Candy's dog because it's old and smells bad. When Candy balks at killing the dog himself in Chapter Three, Carlson gladly volunteers. He seems to totally lack empathy, the ability to share or understand the feelings and emotions of another person. This is probably because he has spent much of his life on his own looking out only for himself and never considering the feelings of others. Slim notes early in that same chapter that he never sees men traveling together the way George and Lennie do. He further explains that the workers who come to the ranch "Never seem to give a damn about nobody." Carlson kills the dog without remorse and doesn't even apologize or sympathize with Candy over the dog's death. He simply grumbles that "We can't sleep with him stinkin' around in here."

It is this same lack of empathy which Carlson displays in the book's final chapter after the discovery that George shot Lennie in the back of the head. When Slim arrives he immediately goes to George to attempt to console him, assuring him that he had to do it. When the two dejectedly leave the scene, Carlson can't understand their sorrow. He remarks, "Now what the hell ya suppose is eatin' them two guys?" He has no idea what it's like to have a close friend, and can never understand George's relationship with Lennie. He is symptomatic of the harsh and brutal world which Steinbeck develops in the book.