My younger daughter has dropped her pet rabbit off for a few weeks while she goes off and prepares to get married and stuff. Bunny came with a litter box, a traveling cage, and that's about it. She's a "house" bunny, so tends to run about the place at my daughter's college apartment. So I decided -- who knows why -- I wanted to give it something that got a better balance between being stuck in a wee cage on the one hand, and running all over the place on the other hand, crapping on the furniture as she went.
I think I may have got a bit carried away.
It's built from the modular wire cubes you get from Target and a bunch of other places. A box of 24 wire "sides" costs $20; there are 59 such sides in what you see, so the wire skeleton for the whole thing cost $60 -- three boxes.The wire sides come with little plastic connectors, but they're not strong enough to build that size of structure. So instead I used 8" electrical ties to hold it all together. The rest is some wood from Home Depot (pegboard-style hardboard for the "floors", and some cheap pine for those supporting rods), and a piece of cheap carpet (tight weave so the stupid animal doesn't eat it) from Lowes. Total cost was probably under $125.
I got the idea from here, here, and here. That last one is labeled "large", which means mine may qualify as "humongous".
As I say, I don't know why I did it. I'm treating it as some kind of jigsaw puzzle (which is equally senseless if you ask me, but at least thinking of it in those terms means I'm not alone in my insanity).