Male/female rats and odor?

Im not sure if the males urinate more with females around, they like to leave their smell around anyway, females nearby or not. Be careful about cleaning the cage too much as they dont like the clean smell and will spray to make it more homely anyway. A good idea to help reduce smell is to sprinkle bi-carb soda under the bedding as it helps absorb the smells. Or place a bowl or bi-carb soda next to the cage :) hope that helps you out a bit... oh and apparently you can get some special formula to mix with their water which is not dangerous to their health but minimises the smell or their urine :)