A guy walks into a bar with a chimp. Has a beer and the chimp has a shot. After about four or five drinks apiece, the monkey goes wild and tears the place completely apart. He breaks pool cues, beer glasses, tables, stands in the middle of the pool table and EATS the cue.
The chimp's owner finally gets the chimp under control and the bartender tells him to get out. The next day the guy comes back and gives the bartender a check for all the damages, says how sorry he is and gives back the cue ball.
The bartender thanks him and offers to buy him a beer, but refuses to serve any alcohol to the monkey, and gives him a peanut instead. The chimp takes the peanut shoves it up his ass, takes it out and eats it.
The bartender says, "Now why did he do that?"
"Ever since I got the cue ball back, he's been checking everything he eats for size first."