The teacher was giving her class of seven-year-olds a nature history lesson.
"Worker ants," she told them, "can carry pieces of food five times their own weight. What do you conclude from that?"
One child was ready with the answer, "They don't have a union?"
Summer vacation was over and young Jack returned to school.
Only two days later his teacher phoned his mother to tell her that Jack was misbehaving.
"Wait a minute," mother said. "I had Jack with me for three months and I never called you once when he misbehaved."