The lifeguard told the mother to make her young son stop urinating in the pool.
"Everyone knows," - the mother lectured him, "that from time to time, young children will urinate in a pool."
"Oh really?" said the lifeguard, "from the diving board!?!?"
Crocodiles and alligators are surprisingly fast on land. Although they are rapid, they are not agile; so if you ever find yourself chased by one, run in a zigzag line. You"ll lose him or her every time.