Emma probably likes under the couch as it feels like a nice safe tunnel to a little bunny. Can you set up some alternative tunnels that are bigger, so that she has a new safe place before she grows too big to get under the couch? Cardboard boxes are good for this.

I agree, if there’s a spot that she usually accesses the space under the couch from, put a cardboard box in front of it when you block the rest of the couch. She will be frustrated when you block off the couch, so you need to make sure that when you do it, it is done very securely so she learns quickly that she’s unable to get past it. If it’s weak in any way she will find the weakness and work at it until she can get through (bunnies are stubborn and determined in that way). It’s much easier to block their access from day 1 than to allow them access to something and then expect them to stop using it

I really do think that providing alternatives right next to the couch will be the best solution. Tunnels, boxes etc to give her other places to hide in the same area that she was hiding before.

I would say do it rather than risk it. Oz doesn’t know big his bum is and forces himself into gaps that are so tight he yelps. When he snuck into the kitchen the other day we spent half an hour taking it apart to retrieve him from where he was stuck. Some buns aren’t clever enough to know their size when they’re growing..

It took a while for my rabbit to acclimate to his BB maze and cottage. I think it took him a month to build the courage to go to the top level of the actual cottage, so just give her time. I put exercise weights (plates) inside flat boxes that fit under stuff, and that’s how I ensure either of my rabbits don’t chew carpet underneath, where I can’t see them. Yeah, she will probably be cranky about losing the couch space, but if there’s another safe spot, she will gravitate towards that. You’re doing the right thing for her, and that’s most important, even more than her getting her own way.