Overstayed Welcome

There has a been a possum living in our car port/roof for a while now. At first it was kind of fun to see but then it started pooping on our car and peeing down the walls (Sick!!). We called our landlords to see if there was anything we might do to get rid of him. The problem is they are a protected animal so you can't just shoot them or trap them or anything inhumane. Our landlord heard that they don't like the smell of moth balls (me either) and if you hang them where they like to sleep they will go away. Our nice, little 85 year old landlord came over one day to hang them up all over the place (we don't have a ladder so we couldn't do it on our own). The next night he was back again like he owned the place. I have a feeling the smell doesn't bother him...