I have been playing mousehunt for awhile. I enjoyed it very much, although it's not interactive but it's attractive and you can have fun together with your friends talking about the mice you caught.
So I made a simple userscript to help me click the horn. The script helps you to actually click the "Hunter's Horn" instead of calling the sound the horn URL "http://app.facebook.com/mousehunt/soundthehorn.php" to avoid being detected as bot clicks. The script is to use with firefox web browser.
You can get the script from here [http://userscripts.org/scripts/show/54954].
Enjoy!!
