Self trained litter box rabbits?

[Bunnychick]

Adopted my buns at 2 months, 2 of them sharing a small cage and just moved to a jumbo 2 mo later. They seemed to have established a litter box area, I just line and lay bedding. Is there a need for a box?

 

[BuckzBarnYard1983]

Box might be nice to keep things tidy. In my experience buns like to be kept nice and clean. So my two cents is to go with a litter box.