my bun Sienna either isn’t completely litter trained or her litter box is too small. if it’s the latter, i’m getting her a new litter box in the future anyways. moving on..
because Sienna doesn’t always use her box i have puppy pads set out in two different spots where i also always have hay available for her to munch on – one in her cage area underneath her hay rack and litter box, and the other out in her play area in the middle of which i set down some hay. you could try setting the hay down to a side of a puppy pad and then whenever your rabbit eats hay he’ll pee and poop on the pad and you can easily fold it up, toss it, and replace it.
i should also probably mention that your bun might tear the pads up – Sienna used to do this but now she rarely does as i’ve started putting a toy in front of her face to interrupt her every time she does it. if you decide to try out the puppy pads and your bun starts munching on them, you can always try that to get him to stop!