I have a small concrete patio inside my house that is open so it's perfect for the pets (2 cats and 2 dogs) do poop and pee. I went traveling for 2 days and left the pets home and when I came back there was a lot of pee. I was out of cleaner and, since I'm a genius, I used BLEACH to clean the pet piss. Well, we had to evacuate because I just created a chemical weapon inside my house. Almost fainted.