You don't need to buy a hidey house, you canjust give him a cardboard box or get a big grass mat, roll it, and tieit with zip ties to make a tunnel. The dragongrass mats atPier 1 are great for that. My buns also like to lay undertheir shelves, and on one end in both pens I hung paper towel tubeslike a cardboard curtain. They love these and like to laybehind them, chew them, and push them around. You could builda shelf in the dog crate. I used to have one when I used acrate.
Although most rabbits are fine without something to hide in in theircage, some like it and a few need it. When I moved the bunsto their big, open pens, Mocha freaked out and stayed in her grass mattunnel 24/7 until I gave her a couple more boxes. Then shefelt more comfortable moving around because she had a lot more hidingspaces.
Sprite in the grass mat tunnel
Loki playing with the cardboard curtain
I have lots of toys for my buns. Cardboard boxes, especiallybig ones in the living room that are stuffed with hay and newspaper,jingle bell balls, plastic keys, hanging chew toys with bells, wickerballs and baskets, grass mats, all sorts of things stuffed with hay,etc. Check out the toy thread in Bunny 101 for lots of ideastoo.