I just read this. Wow I never knew a female needed several houses to choose from.
Location, location, location!
www.birdnote.org
House Wrens and Dummy Nests
There may be no busier bird during the nesting season than a male House Wren. Just a day or so after completing his spring migration from the tropics, the male House Wren claims a territory and checks out several potential nest cavities. And in each of these locations, he builds a starter nest using virtually anything twig-like to get the job done — from nails and bits of wire to paper clips and hairpins. The male House Wren stays at it until a female pairs with him. Then
she picks one of the starter nests and takes over construction.