You can search for "pest control company". I don't remember how much I paid exactly, probably $500. There are huge diference in price among companies. So, phone several companies and then make a decision. Good luck!
修屋顶的人可能不知道， 要找pest control company. This is a very common problem. Once you tell them your problem, they should be able to tell you the reasons right away. If you hear the noise at night from the attic, 99% you have animal in it.