A) When Lester's little sister starts screaming for no reason, his mom explains that she's just having a tantrum. Lester and the others want to know more about tantrums, so they get out the great big book of everthing and learn about one animal that has the biggest tantrums of all; the Tasmanian Devil. B) Stanley and his friends don't want to wear their life vest when they go on a trip to the beach. So Dennis teaches them how sea otters use their fur as safety when they're in the water.