I do not keep birds, but I have a friend who is having landlord issues. Basically she bought a bird, because it wasn't outlawed on her tenancy. Now the landlord is saying she can't keep it, because of the smell.
Have you kept them-do they smell? What can she do?
maybe if the cage has a better absorbent litter for the bottom (look for corn cob in pet stores)
i know usually people use newspaper, or sandpaper for the bottom of the cage..but if you use something more absorbent, you can clean it once/twice a week (depending how big this bird is), and it wont smell.
there are also bird bath sprays you can use to spritz your bird clean.
I have a cockatiel and she doesn't smell at all. Now she does have a birdy oder but you have to put your nose right on her to smell it. It's not bad at all.