Have two swans in our neighborhood in Pennsylvania, breed every year and are very productive. The nest is built on an island in the middle of our pond, but some neighbors suggest we build a "house" for them on the island. Question - Will the swans use ithe "house" or not? Hate to have something they won't even use? They've been with us for a number of years with no problems so please let us know whether to proceed or not. Thank you so much, Elizabeth