Ralph Lauren Femme Manches Longues length and width

Hello! I have a 5 month old male ferret. I am trying to litterbox train him but i was told that the only way to train him is with treats,
Ping K15 Driver, but he doesnt like treats so how can i train him then? Also in a book i read it said that ferrets need a cage with a lot of floor space (length and width) as oppose to a tall and narrow cage for climbing. The book says that ferrets are not climbers.