While seeking their lost dog, Piddle, twins Josh and Danny encounter their next-door neighbor, Petty Potts, a mad scientist whose SWITCH spray accidentally turns them into spiders.
Mad scientist Petty Potts asks her neighbors, twins Josh and Danny, to help with her experiments and when her SWITCH spray turns them into flies, they are able to investigate the sabotage of their mother's garden.
After accidentally drinking some of mad scientist Petty Pott's SWITCH potion while at school, twins Josh and Danny become grasshoppers and this time they may not change back without help.
During an unwelcome visit, neighbor Tarquin unwittingly uses SWITCH spray to turn twins Josh and Danny into ants, then sets out with a magnifying glass to fry some bugs.