How to fix the hole in the foundation, where mice are entering?
Make some mortar. 3 parts sand, 2 parts Portland cement, 1/2 lime. Add a little water till it’s like peanut butter get the blocks wet then fill the hole with mortar. This is way better than premixed.
Steel wool with cement or spray foam. Call an exterminator or crawl space company. We had rats destroying our ductwork and crawl space and we had to pay 7k to get it fixed by removing the nests and insulation and ducts and new metal ductwork put in to replace the flex duct we had. Imagine the sound of rats scurrying around your ducts at night and your cats just staring at your vents.
They have spray foam with rat poison in it.
Steel wool in the hole temporarily will stop them from coming in until you figure out how to fix it.
Mortar mix not concrete. Cheap easy wet block before filling hole. Just put it on a small board against the block and stuff it in. Steel wool outside will rust away over time.
You can fix the hole in the foundation using steel wool and then caulking it.
You could close the whole with quick crete, but stuff it full of steel wool first then patch.
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