Pearls Before Swine by Stephan Pastis for August 21, 2010
Rat says, "What do you got there, Pig?" Pig says, "It's my deceased friend, Willy the Woodpecker. I guess he just wore himself out constantly banging his forehead into a tree." Rat says, "Woodpeckers don't use their foreheads. They use their beaks." Pig says, "Willy would have found that information useful."