How to Build a Bento Box

So after reading Bento Rats for a few weeks you've found yourself drawn, unexpectedly perhaps, to the intelligence, energy, and cuteness of rat and now you want your own. If you've priced anything from aquarium tank toppers to multi-level auto-cleaning Gucci emblazoned habitats you know that they are not cheap. The lowliest rat-suitable cage will run you about $60, only have one level, and have very little room for expansion or play. If you've been reading Bento Rats you might have guessed at the reason: their teeth. A rat's teeth are harder than iron, and grow at an alarming rate. Rats don't wear their teeth down by gnawing on things (they can chew through cinder blocks if they put their minds to it) but by the action of the teeth against each other. So any old hamster cage couldn't hope to contain a rat; you need a cage with a wire gauge more suited to rabbits, or bolt cutters (Note: bolt cutters make boring pets). Rats are also escape artists, so any cage has to have bars much closer together than a traditional "large rodent" cage would have.

The upstairs and downstairs are connected by the ramp in the back

After examining the factors we decided that we could build a cage for less money that would be larger, more secure, and have more room for play and expansion. I think we hit the mark with the Bento Box and though I didn't document the process exactly, I can probably sum it up well enough to get you started on construction of your own rattastic habitat.

I started with an old bookcase. It was one of two nearly identical rolling bookcases that we had on hand and were using to store junk in the basement. You can find similar bookcases at your local home store, but I'd check craigslist or yard sales first, since we are trying to do this for less than $100. In order to make sure Sushi and Sake have plenty of air circulating in their cage I wanted to use wire to enclose the front and back of the cage where possible. After measuring the height of the top and bottom shelf of the bookcase and drawing up some rough diagrams, I headed to Home Depot for supplies.

The water bottle and cage sides attach with metal clips and springs.

I picked up one 6' length of wire shelving and a sheet of LEXAN to use as the walls of the cage. These items were expensive, but the shelving had the correct gap between wires and was sturdy enough to withstand any rat chewing. I have experience working with LEXAN on arcade cabinets and controllers, so I thought it would be a good option for one level or another. I also picked up a length of pine trim to use as a ramp and assorted screws and eye hooks.

In order to make a ramp up to the second floor I cut a suitable hole in the shelf, and attached a ramp with a bit of piano hinge. This works well for cleaning because you can wipe out the cage and the ramp moves out of the way. If for some reason you need to separate your rats, the ramp can also be raised to divide the cage into an upstairs and downstairs section.

The top floor has the PVC swing and the nest.

After trimming the shelving to size using a hack saw and my pet bolt cutters, I attached top and bottom doors using the standard fasteners made for attaching the shelving in a closet. These metal fasteners worked out really well because they allow us to swing the top and bottom doors out for cleaning. The rear of the cage has wire on the bottom section and is locked in place with a few more fasteners than the front. The top section of the cage is a piece of cut Lexan (plexi-glass) that is attached around the edge with small finishing screws. The key to working with Lexan is to score it with a blade, then clamp it between two stiff boards or metal bars before snapping it off to size. Drilling pilot holes is also a smart idea because it can crack if you try to screw directly through it. If you don't have very sharp bits, consider using a dull bit running backward. It won't leave as clean of a hole, as it melts through, but it won't crack either.

To lock the cage, each door has a length of salvaged closet shelf wire bent into a hook and attached to the cage with a small spring. This allows us to open the top and bottom independently or together depending on what we need to do in the cage. The water bottle is a standard rodent bottle that is fed through a hole drilled in the side of the cage and held up with the spring it came with and a couple of eye screws in the side of the cage.

I also created a swing from a PVC T-Joint by drilling a few holes and feeding more salvaged closet shelf wire through them to create grips. I drilled a few more holes in the PVC and hung this from the top of the cage with wire. The girls love to climb on and in it and the wire provides enough swing that it's fun, but not so much that it hits the side of the cage. We use cheap dish towels as bedding in the cage and while they aren't perfect, the rats do a pretty good job of using their litter tray, so more often than not the towels get used as toys. Initially I had the idea that we would use Velcro to attach the towels to the cage but that plan was almost immediately abandoned as being too much to deal with and ultimately unnecessary.

Overall we spent about $60 on parts for the cage and another $50 on extras like the water bottle, wheel, nest, hammock, and litter tray (which we would have had to buy regardless). In the end we have a cage that is far easier to clean than an aquarium and gets much more ventilation, plus it was significantly cheaper than a cage of similar size. It also turned out looking far more professional than I had anticipated, which is a definite bonus. The most obvious reason I think it's been a success however, is that Sake and Sushi seem to really like it

If anyone has any questions, post them below and I'll try to answer them all.