My cat discovered that window screens are not solid walls. He launched himself at a moth on the other side of the screen and left a gash the size of my hand. Mosquitoes had a free pass into the bedroom for three weeks before I finally fixed it. Three weeks of buzzing in my ear at 2 AM. The fix took five minutes.

Two repair methods, depending on the damage

Small holes and tears: Screen patch

For holes smaller than a quarter, a stick-on screen patch is all you need. Hardware stores sell them in little packets for a few dollars. Clean the screen with rubbing alcohol, peel the backing, press the patch over the hole from the outside. Done. The patch is nearly invisible from a few feet away.

One thing: patches work better on fiberglass screen than metal. Metal screen is slick and the adhesive peels over time. For metal screens with small holes, a drop of clear super glue bridges the gap — ugly but functional.

Large tears: Replace the spline and screen

If the tear is longer than an inch, you are replacing that section or the whole screen. This sounds harder than it is. Here is the process:

1. Remove the screen frame from the window. Most frames lift out by pulling the tabs on the sides.
2. Pry out the old spline. The spline is the rubber cord that holds the screen in the groove. Pick it out with a small flathead screwdriver starting from a corner.
3. Pull out the old screen. It will come right out once the spline is gone.
4. Cut new screen material. Fiberglass screen is cheap — a roll costs about ten dollars at any hardware store. Cut it two inches larger than the frame on all sides.
5. Press the new spline into the groove. Lay the screen over the frame. Use a spline roller — a little double-wheeled tool that costs five dollars — to press the rubber cord into the groove. Start in one corner and work your way around. Keep the screen taut but do not pull so hard it bows the frame.
6. Trim the excess. Utility knife, run flat along the outside of the spline groove. The blade cuts the excess screen cleanly.

The whole thing, start to finish, is about five minutes per screen. The spline roller and screen material cost less than a pizza, and you can rescreen every window in your house with one roll.

My cat still attacks moths through the screen. But the screen holds. He has not figured out how to open the window yet. I am giving him another year.