What angers George about his bunk?

If I remember correctly, it is to do with the fact that when he looks at it he finds a spray can for something like lice or some other bug killer. He believes there may be something wrong with the bed, hence why he complains.

Although as it happens, it is to do with the fact that the ranch worker that worked there before was a very clean worker and cleaned himslef reguarly hence why it says later on that he cleaned his hands and feet before and after his meals, and on Sundays he would wear very formal clothing even though he didn't go anywhere, also suggesting that he may have had some religion, which Steinbeck may have used to help set the American 1930's theme...