1. Cut a hole in the side of a large cardboard box.The hole should be big enough for your bunny to fit through easily. If you want you can also add more entrances on the other sides. If you have a big enough box, but a smaller box inside the bigger one so your bunny can climb on top of that one or inside it. Put small toys and treats hidden in the smaller box or just in corners. Your bun will love climbing around and exploring his or her new hide-out.