Litter sizes can vary greatly according to species and environment The Arctic fox, for example, can have up to eleven kits but exceptionally contain as many as 25 (the largest litter size in the order Carnivora).
Foxes are strange in the way that it would be hard towards impossible to litter train them, however if you have a cat or a dog that is litter trained the fox will (if you purchased it as a youth) learn to do the same.
Red foxes reproduce once a year in spring. The average litter size consists of four to six kits, though litters of up to 13 kits have occurred. The lifespan of the Red Fox is 2 to 4 years in the wild and 15 years in captivity.