brianna , who had seen mrs. bug 's unceremonious exit and come up to investigate the cause , began humming softly under her breath-a song to which memory promptly supplied the words , `` oh , he 'll sleep 'til noon , but before it 's dark ... he 'll have every picnic basket that 's in jellystone park ... '' i pressed a napkin to my mouth , ostensibly to blot the remains of the tea .