What words and phrases help create this mood?

They made their beds on the sand, and as the blaze dropped from the fire the sphere of light grew smaller; the curling branches disappeared and only a faint glimmer showed where the tree trunks were. From the darkness Lennie called, "George-you asleep?" "No. Whatta you want?" "Let's have different color rabbits, George." "Sure we will," George said sleepily. "Red and blue and green rabbits, Lennie. Millions of 'em."