illustration_base(/album/blog/ratcage/) picture(p1070523, w)

Our first rat cage was a small one we picked up at the pet store when we bought our first two rats. As our rats grew, it became obvious that we needed something bigger. Big cages are expensive, so I built my own. Since then I rebuilt the cage once from scratch. This page describes my improved design.


  • Sizable plastic box, with lid, to build the cage in. You'll want to find one that isn't very high, but preferably wide and deep.
  • Roll of 1/2 inch hardware cloth. You can save yourself a lot of work by getting a roll that is as wide as you want the cage to be tall. Common widths are 3, 4, and 5 feet.
  • 1/2 inch (schedule 40) PVC. I think the 1/2 inch refers to the inside diameter of the pipe, but mine seems a little bigger than that. It's the common stuff at the hardware store, sold in 10 foot pieces.
  • 8 PVC corners ("side outlet 90s")
  • 4 PVC elbows for each shelf
  • Bag of 100 6 inch cable ties.
  • Length of 1/8 inch thick 3/4 inch wide zinc plated steel. Exact dimensions aren't that important, as long as you can attach it to the hardware cloth, and as long as magnets will stick to it. You'll need 4 inches of length for every door.
  • 4 strong magnetic discs per door, 3/4 inch in diameter and 1/8 inch thick, preferably coated with something. I bought these. You can buy two magnets that are twice as thick instead, but I couldn't find any coated ones in that size.
  • If you're hanging your shelves with method 1: 2 key chain rings, 2 threaded rods a little longer than the depth of your cage, and 4 nuts that fit the rod per shelf.
  • If you're hanging your shelves with method 2: Some 12 gauge solid core copper wire (coated).


illustration(p1070527) The lid of your storage bin will be the cage's roof. The bottom will be its floor. Build a box frame using the PVC pipe and PVC corners that fits snugly in the bottom of the box. The frame on our cage is slightly odd because our storage box has wheel wells in the bottom. Push each fit together tightly and you won't need glue. Cut a roll of hardware cloth as wide as you want your cage to be tall, if those aren't the same. I wouldn't cut the length just yet, because you'll be surprised how much more you'll need than you think to just wrap around the cage.

After cutting the hardware cloth, you'll be left with sharp points at the end of each wire. You can deal with them in 2 ways. The first is to fold each wire that sticks out back onto itself. The second is to just cut them as short as possible and use a metal file or sand paper to soften the point a bit. The former method works better, but is a lot more work.

Use cable ties to connect the hardware cloth to one vertical side of the PVC frame. Wrap the hardware cloth around the frame, securing it with cable ties as you go. Stretch the hardware cloth as taut as you can. I used cable ties every 5 inches or so. Cut off any hardware cloth you have left over once you wrapped all the way around the frame. Put the frame in the storage box, and put the lid on top. Admire your work.


You'll want to cover almost the entire front of the cage with doors. If you don't have enough doors, it can be a real pain to access certain parts of the cage without taking the whole thing apart. Unless your cage is really narrow, you should have at least 2 doors side by side so that you'll have a stable piece of cage to attach shelves to. In our current cage we have 2 doors on the bottom, and 2 doors on the top. Each door opening is just over 12 inches by 12 inches. I wouldn't make doors much bigger than that because they might be too flimsy. Don't make them too small because it's really handy to be able to get an arm in all the way. Before you start cutting anything, remember that the door itself is going to be bigger than the door. The door take up two squares to the left, top, and right of the door.

illustration(door_opening.png) To cut the door opening, cut a hole that is 1 square smaller than the door opening will be all the way around. After you clean up all the sharp ends, cut two wires in each corner like in the picture. Finally bend the 1-square wide strips around the doorway 180 degress back into the cage. The picture shows a door opening of 15 by 8 squares (7.5" by 4"). The blue lines indicate where to bend the strips backwards.

illustration(door.png) For the door, cut a rectangle that is 6 wider and 3 taller than the door opening. Cut out the top right and top left corners. In the bottom corners cut out a 2-square strip, as pictured. Clean up sharp ends, and then fold 1 square wide strips on the left, top, and right of the door out 90 degrees. This will make the door a lot more rigid. It pays to sketch out what you're going to cut before you do it. I didn't so all our doors are not even, and some don't overlap as much as they should. The picture shows a door of 18 by 10 squares (9" by 5").

illustration(p1070525) Next attach the door on the bottom of the door opening with several cable ties, so you can see how everything fits and overlaps. Take the piece of steel, and cut two 2-inch long pieces. Drill a smallish hole near the edge of each one. Use cable ties to fasten these to the cage just outside the top corners of the door opening, like in the picture. Finally, close your door and stick 1 or 2 magnets in each corner. Admire your work.

Next time I make a door I will probably add a little flap in each corner to hold the magnets down. They do occasionally come off when we open a door too quickly.


The shelves are pretty straightforward. Make a rectangular frame out of PVC and and PVC elbows, taking care that the width is the same as the depth of your cage so the shelf will fit in the cage snugly. Then cut a rectangle of hardware cloth of the same size, and attach it tightly to the frame. Now you have a choice of 2 different methods to attach the shelf to the cage. We put cardboard in our shelves, which we replace every few weeks or as the rats tear it up.

Number 1 uses threaded rods. Attach 2 key chain rings to the bottom of each shelf, so that their opening faces the front of the cage. Now take a threaded rod. Put a bolt on one side, stick it through the back of the cage, through a key chain ring, and through the front. Then put a bolt on the front. Do the same for the other key chain ring. This firmly attaches the shelf to the cage, but it's a bit of pain to move the shelves around.

illustration(p1070526) Method number 2 uses firm copper wire. Cut of 4 or 5 inches of copper wire, and bend it into an S shaped hook. Hook to the side of the cage, and the shelf. Do this 4 times to hang one shelf. This method is much more flexible, and it's a bit easier to move the shelves around. However, it doesn't mount the shelves as sturdy and occasion we've had a shelf fall down because we didn't attach it strongly enough. This leads to very confused rats.

In our cage we also have one permanent level in the middle. It just consists of a piece of hardware cloth that divides the top of the cage from the bottom. There's a hole on one side to let the rats get through. This also allows us to turn the cage into two parts, in case one of the rats is sick, simply by blocking up the hole.


I don't have ramps quite figured out. I have some ideas in my head, but haven't tried it yet. In the old rat cage I had a staircase, which worked very well except that it was a lot of work to take out to clean. If you build this, keep it in mind when you put in the doors of your cage, because this design has to be fastened to the side of the cage permanently. To build one of those you'll need more hardware cloth and cable ties, as well as some fine mesh plastic hardware cloth (which is used in screen doors etc). The staircase consists of landings and ramps.

illustration(crw_8778) To make a shelf, cut an 18 by 10 square piece out of hardware cloth. Be sure to leave excess wire sticking out all the way around. Cut away the corners.

illustration(crw_8781) Bend all the excess pieces of wire to one side.

illustration(crw_8786) Cut a piece of fine plastic hardware cloth that's bigger than the piece of metal hardware cloth, and press it onto the bent pieces of wire.

illustration(crw_8787) Bend all the bent pieces of wire to the other side of the shelf, flattening them against that other side. A few pieces of wire may break off. Now the plastic cloth is securely fastened to the shelf.

illustration(crw_8793) Bend one square's width towards the bottom of the shelf, so you end up with a very shallow basket. This makes the shelves quite sturdy.

To make ramps for in between the landings, just build a landing of a different size and change the very last step. Instead of bending all the way around the ramp, just bend the long sides. This results in a shallow trough instead of a basket. If you bend in the ends as well, then they will be in the way when attaching the ramps to the shelves.

illustration(crw_8798) Finally, attach it all to your cage with cable ties. I found it best to attach all the landings and ramps together first, so that you can easily see where on the cage to attach each landing.