Mr. and Mrs. Peabody invite a guest to dinner, but Maybelle the cockroach, who lives under their refrigerator, ignores the warnings of Henry the flea to be sensible and ends up "splashing" into a big adventure.
When a giant cockroach named Max escapes from their mother's bug laboratory, Leo and his brother receive help from a mysterious stranger who advises them to think like a bug in order to recapture the runaway roach.