When this whistle is blown, it summons the closest two giant rats up to one mile away, to the users location.  It can only be used once per day.  The rats summoned act of their own volition once they have arrived and are not under the control of the whistle blower. 

Any effects (magical or otherwise) that would silence the area where the whistle is blown prevent it from working.

Notes: Summoning, Communication, Utility, Jewelry, Instrument