Mice Are Moving Into Your House RIGHT NOW, Seal These 5 Spots Before the First Frost

It is a Tuesday night in November. The house is quiet, and then you hear it. Up in the ceiling, or in the wall behind your headboard. A scratch, a little scurry, and then again. And you lie there in the dark and feel it in your stomach, because now it is INSIDE. Now roll that night back. Back past Halloween, to today, a warm afternoon in September, when that mouse is still out in the field and has not once thought about you. Mice do not move in when it gets cold. They move in the WEEK of the first frost, when the ground goes cold and the seed heads are gone and the warmest thing for a mile is your wall with a furnace behind it. And they get in through a handful of gaps that are sitting open right now, that you can find and close in one Saturday for about thirty dollars. The man who seals in September never meets them. 🐭 THE TWO THINGS THAT CHANGE EVERYTHING: • A mouse does NOT chew a new hole through your house. It widens a gap that is already there, and chews soft things like foam and plastic. The gap is the enemy, not the mouse. Close the gap, and there is no door. • A grown mouse needs a gap the size of a DIME. A rat, a quarter. If a pencil goes in, a mouse follows it. You are not looking for holes today. You are looking for things you never would have called a hole. 🔦 THE FREE TRICK (do it tonight): every light in the house OFF. Somebody inside with a flashlight held low along the bottom of the exterior walls, the basement, the garage. You outside in the dark, walking the house slowly. Every gap glows like a little star on the foundation. Mark each one with chalk. That is your list for the weekend. THE 5 SPOTS, IN ORDER: ① THE GARAGE DOOR CORNERS, the #1 front door in America. The bottom seal is flat and the corner is not, so there is a dime-sized triangle at each side, eight inches from your warm house, with the dog food and bird seed on the other side of it. Fix: corner rodent-guard pieces (a few dollars each) or a fatter bottom seal plus sheet metal at the corners. And every bag of seed and feed in the garage goes into a METAL can. Plastic is a snack. ② WHERE SIDING MEETS FOUNDATION. Walk the whole house low at that line. Small gaps: steel wool or copper mesh packed tight with a screwdriver, then caulk. Bigger: quarter-inch hardware cloth cut with snips and sealed. ⚠️ Brick house? Those little vertical slots low in the mortar are WEEP HOLES and they are supposed to be open. Never caulk them. Push in the mesh inserts made for them. Same for soffit and foundation vents: mesh, never caulk. The house has to breathe. ③ THE DRYER VENT FLAP. A flap glued open with lint is not just a fire problem. It is a warm four-inch tube blowing gentle heat straight through your wall. To a mouse that is a hallway with a heater in it. Clear it, make sure it falls closed on its own, replace the hood if the flap is broken ($15). And do NOT put a mesh screen over a dryer vent, it packs with lint and becomes a fire. The closed flap is the door. ④ THE PIPES. Every pipe and wire through your wall goes through a hole cut bigger than the pipe: the AC line set, outside faucets, gas line, cable, electric service. The mouse walks in AROUND the pipe. Finger test at every one. Steel wool packed around the pipe, then caulk, or a cover plate over the whole hole. Do the same under the kitchen sink and bathroom vanities where pipes come up through the cabinet floor, that is the door from the crawlspace to your kitchen. ⑤ THE DOORS YOU WALK THROUGH. Lie on the floor inside with the porch light on. Daylight under the door is an open invitation. A door sweep is ten dollars and five minutes. The garage-to-house door first.