If someone knocks on your door and says he is an animal control officer, you won’t immediately know if he is at the wrong address, is someone impersonating an ACO or if he has legitimate cause to knock on your door. Regardless, your response should be the same: Do not let the person into your home unless he produces a warrant granting him entry. If you decide you feel safe speaking to the ACO face-to-face, get your house key, a pen and paper, and secure any loose pets. Inform the ACO you will be coming outside and politely ask him to step back from your door. Lock the door behind you.
Once outside, listen to whatever the ACO has to say. Do not answer any questions outside of your name. Do not lie. If necessary, reiterate the fact that you are not giving permission for the ACO to enter your home. Exercise your right to remain silent. Do not admit owning any banned breed or pets over the local limit. Do not defend yourself against any accusations. Remain silent. Write down the ACO’s name, badge number, and the agency he represents (county animal control, city police department, etc.). If there is more than one person present (another ACO, a police officer, a humane society staffer, a neighbor who saw what was going on and came over, etc.), write down all their names and organizations.
If the ACO had no warrant and you refused him entry and refused to answer his questions, you should expect a return visit. In the meantime, find a family member, friend or other safe place for any dogs who may fall under a local breed ban as well as any pets in your home that put you over the legal limit if your area has one. Tidy up your animals, crates, x-pens, litter boxes and your home in general. Make sure your animals’ records are in order so that you can produce documents if required (e.g. proof of rabies vaccination, proof of neuter if your area has MSN, local license if applicable). Don’t panic. Contact an attorney for advice if you are able.
For detailed advice that goes beyond the basic points mentioned here, read “What to Do When Animal Control Comes Knocking” by attorney George J. Eigenhauser Jr.