How long can Clothing moths lay dorrmant?

[Tim_Stuns]

I have a friend who is a bit paranoid of bugs.  She would like to move 
some furniture from a place that had moths about 2 years ago.  She has
not been to the place since but others have and its been fumigated.
No one has seen any sign of them again.  Is it possible for any 
of these to be lying dormant in any of the furniture?  Also concerned
about felt in grand piano:)