It's 4 stories devided meaning that the boys have the 2 bottom floors and the Girls have the 2 upper levels since their was a mishap in sexing and I am not willing to part with any of them. Right now I only have 2 boys in the bottom half and 1 female in top two but looking for anothe female so she can have a buddy for that is if her baby(s) are not female. The 3 grids in the middle of each row opens to allow feeding, cleaning, and caching piggies.