When the kids won't stop being loud, Mouse uses an invention that causes the others to swap voices so they can hear how irritating they sound. At first the kids have fun with each other's voices, using them to playing tricks - but how will Boy get through school when all he can say is ‘meow'?

Boy realises that the family doesn't have any kind of safety drill to use in an emergency, so he decides to train the family to become a well-oiled safety machine. But with the kids so busy practising the new drill, nobody hears the news about an escaped lion heading their way...