Rat Shield gives protection against rats, mouses and all so forth.
It produces sound effects rats can't stand - e.g. high frequency ultrasound that is used for warning other rats about present danger.
For more scientific facts see e.g. "Principles of Rat Communication: Quantitative Parameters of Ultrasonic Calls in Rats" from Stefan M. Brudzynski (http://www.cursoecologia.ufba.br/Arquivos/Comunicacao_Animal/rat_communication.pdf)