Build A Rat Playpen

Obtain four sheets of hardboard, 4' long by 2' wide. 1/8" or 1/4" thickness. Places such as Home Depot should carry this in stock.

The 2' dimension will be the height of your pen's walls. I found I needed the two-foot high walls because we had one rat that was a jumper. Even then, she managed to reach the top of the wall a few times.

Cut slots at 1 1/2 or 2" from each end (whichever measurement you choose, do it consistently on all cuts), 1' in length. The width of the slots should be the same as the board thickness. If you have access to a saw, you can cut the wood yourself, but if not, you can usually get them to make the cuts in the store when you are buying the wood.

Have someone help you hold up two boards parallel to each other, with the slots up.

Take another board and flip it with the slots downward. Slide the boards together by interlocking the slots.

Perform the same interlocking of the boards on the other side. You should now have a square pen, approximately 4' x 4' (slightly less because of the 2" offset for the slots).

Your pen needs a floor. You can get a 4' x 4' sheet of hardboard and cover it with vinyl tiles, or perhaps a sheet of linoleum.

Another option is to use a large fleece blanket.

Lay this floor cover on your room floor, and then carefully move the pen on top.

Fill with safe toys for your rats, and you're done! Let the fun begin!

Of course, make sure you or someone else in the household is always supervising, just in case you have a jumper too or if a dispute breaks out.

If jumping is a problem, consider building a lid for the pen with a mesh screen to allow for air ventilation.

Be careful of bumping into the pen or moving the walls while the rats are playing... you don't want to accidentally catch a tail or paw under the boards.

Give them a variety of fun but safe toys to play with, and perhaps a hanging hammock (like those sold by Little Mischief Rescue), for older ratties to take a breather.