We had to put a litter box in our bedroom because Laelia kept peeing on our 19 yr old's clothes and shoes and he was fed up with it. I'd resisted putting one upstairs for years because there's no room for one and I didn't want the smell by our bedrooms, but there's NO SMELL! My nose is SUPER sensitive and even when I hear them using it in the middle of the night there's no odor. We use sWheatScoop litter, which might be a factor, but I'm sure it's mostly because of the homemade food. 
