What do Steinbeck's first descriptions of George and Lennie tell us about their characters?

The descriptions of the two men reflect their personalities. Steinbeck often uses animal imagery like "bear paw" to describe Lennie After walking into the clearing, Lennie's first action is very animal-like. He falls to his knees and slurps water from the river, just as a horse might, or a dog drinking water from a bowl. George comments:

"You'd drink out of a gutter if you was thirsty."

George is described as having quick movements and always on alert.