Staci...My cats hid for the first week that Bella was here. Trevor hid under my bed on the second floor and Andy hid in the basement. Bella was on the main floor, so I had one animal on each level. I was concerned about "bodily functions" too so I put a litter box and food and water in my bedroom for Trev (Andy had full access down in the basement because that's where their food, water & litterboxes are). I checked the litter boxes like a hawk and for the first day or two nothing was disturbed. I was starting to get very worried too. You never saw anyone so happy as I was when I finally had to scoop!