I keep a colony of around 50 breeders in my attic right now. There's a window box fan that I use during the summer. In the winter I just crack the window a bit. Cages are changes every other day. I hate the smell and I have a generous brother/employee that I have do the fun stuff Like that. Although when it was just me I spot cleaned daily with my shop vac. if you walked into that attic and didn't go around the corner to that area you would never smell them.