Secret Passageway Question

[cubs99111]

No: HPFGUIDX 114978


I know that this question is a little out of left field, but I just 
thought about it today.

In POA, Harry takes the secret passageway behind the humpback witch 
that leads him into Hogsmeade.  Now since it seems that Fred and 
George know about this because of the Mauraders Map, wouldn't it 
stand to reason that Wormtail also knows about this secret passage.  
Why wouldn't he let the Death Eaters and Voldemort know.  It would 
seem to me that this would be a fairly easy way to invade Hogwarts.  

Has this ever been addressed?  


JR