How to make buns use litterbox inside the cage?

[MattMouse]

So my buns have a litterbox inside their cage. They use it. Mostly. They also equally like to litter outside the box in the opposite corner of the cage, so i get two piles of poop and have to drag out the entire cage bottom every other day to get it all clean. That's a pain because the tray is 2 feet by 2 feet and just unwieldy to try to dump into a garbage bag. Plus, it's a little annoying that I waste a garbage bag every couple of days to dump the cage bottom and have to tie off the bag to control the smell, instead of dumping the litterbox into a grocery bag and slowly filling a garbage bag to be thrown out at the end of the week. Is there any way to convince them to stop going outside the litterbox? I moved the litterbox a couple of times to try to figure out the best spot, but even when I moved it to that opposite corner, they hopped over to where the box used to be and did the same thing anyway. Help?

[Luckybunny]

Do you just have the two buns....(in picture)? Is it possible that they are each using a separate corner of the cage. You may have to get two litterboxes. Sometimes it is better if they do have separate boxes so you can monitor their eliminations. If they get ill you will know who is doing what by the box they are using. Good luck.

[MattMouse]

That could be the case, but it would also mean making almost the entire bottom of the cage their litter if I put two boxes in. I didn't think that was going to teach them to use one designated place. =/

I'll be building them a bigger cage in a few weeks, so I guess I'll have to consider this possibility now and adjust my cage plans to allow for two separate boxes.