Does anyone know how the FN single unit cage is for rats? Is it big enough, wide enough, etc? I would use a cage calculator, but The dimensions are screwed up on the site Im using
It's a great cage. The only thing to be weary of is that it has a 1 inch bar spacing so if you have young rats or small females they will be able to escape. To solve this you can either use hardwire mesh or you could look into getting the Critter Nation (1/2 inch spacing) also by Midwest.
The single can hold 5 females or 4 males, since I usually like to give males a bit more space.