Have you tried willow hide outs? My buns go crazy for them. They also love cat beds and cat cubbies. Mine also love any kind of basket (make sure there’s no finish on them) I made them a little teepee out of a basket and fleece.

(Edited by Forum Leader Wick to unbold all text)

or cat/children tunnels

Some buns like to be able to see out of their hideouts. My local rescue uses laundry baskets with holes cut out and sanded down. The bunnies really like them because they feel protected but can see what’s going on around them. 🙂

I recently got a cat house from ikea. It’s the same felt material as the fabric under our couch that she likes to hide under. She just doesn’t go in that hideout to hang out. I’ve tried to move the cat house around so the back is facing a corner, so the view would be the same as if she was hiding in a corner. I have no idea why she still doesn’t like it.

Throw in hay and some treats to entice them. I did this while I was petsitting now my friend always does it to the packaging box when her hay gets delivered. Her buns love it.
Both of mine love this pot holder for some reason, also they like just the soft flooring (I used memory foam bathmat as I hear it’s nice for their feet) with a cardboard roof over it. https://imgur.com/RdkukxH

When my bun was solo, she used to sleep in her tunnel all the time, but she sleeps on the foam mat with her bf most of the time now.

maybe try putting a box so the top of the box is on its side maybe shell like that