buttocks

During a family walk around the neighborhood, Jackson suddenly stopped and exlaimed,
"I figured it out!  I know why they call them "buttocks"!!    When your butt feels a poop, it sends a message to your brain.  Your brain then sends a message to your feet to get to a bathroom quick!  Then your brain sends another message to your butt that its good to go.  Buttocks.  Your butt talks.  Your butt is like a walkie-talkie."