Eek! A mouse. I have been in my house since 1976, and never had a mouse until now, when I found a dead mouse behind a sofa. Then in the family room I found a live one, and dispatched him. I called an exterminator, and before he arrived I found another live one, and dispatched him. The man suggested I put in traps on the sill in the basement, which is next to the family rooom. I did, and for two weeks I got nothing but empty traps with the peanut butter bait untouched. Now what? How do they get in? MAD AT THE WORLD, Brockton Why do insects and other critters get in a house? Because they are seeking warmth, moisture, and food, and there is virtually no house that is mouse- or insect-proof. The location of the traps on the sill of the basement may not be the best place for them. So, place them on the floor of the basement, and maybe on the floor of the family room, in areas where mice tend to travel, well against the walls. If that doesn't work, put some D-Con down in the basement and perhaps in the family room. Keep pets and humans away from the D-Con and traps. There is an old saying that says if you see one mouse, you have 20. Another old saying, unknown by many people, is that mice are incredible climbers, so it is not surprising to see them in attics. The interior bottom of my favorite casserole has chipped. It is made of cast iron, with enamel coating on the exterior. Do you know if it is safe to use and to eat food cooked in it? Also, the finish on my 2-inch oak kitchen floor, installed and finished in 1991, held up well for 14 years. By 2004 it had lost its sheen, so I had it refinished by a firm that cleaned it, buffed it, and applied three coats of polyurethane. It lasted fairly well for four-and-a-half years. I hired the same firm to redo it last December. A different manager assured me only two coats were needed, after cleaning and buffing. He was so wrong; it looks as if it needs polishing again. So I wonder what I can do to maintain my kitchen floor without enduring the ordeal of refinishing. What cleaners and polishers would best maintain my very good oak floor? ACG, Belmont The chipped cast-iron casserole is safe to cook in. Mankind has cooked in unfinished cast iron for millennia without ill effect. I think it is a benign material, and a very good one, for cooking. As for the varnished floors, forget about cleaning and buffing or refinishing polyurethaned floors. Generally they do not need it, and a well-finished hardwood floor should look good for a lot longer than 14 years. A dull floor can be buffed with a buffing machine with a lambswool bonnet. To clean it, wash it with a wet Swiffer, which will allow a small amount of water to clean with. I think one of the problems is that the polyurethane is water based, which is not as sturdy as the old oil-based polyurethanes. I assume your floors are bare; I think if you put rugs down, the floor will last for many more years. I live alone and have a steam boiler. My late husband used to do all the house chores, so now I have to learn them. I have to fill the boiler once a week to keep the water up to the line in the glass vial on the boiler, which is 20-25 years old. What should I do? NOT-SO-MERRY WIDOW Keep filling the vial. I think that boiler has quite a few more years left in it, so one thing you can do is to get another opinion. And find a plumber who might be able to put in an automatic feed valve. Such a valve will add water to the boiler whenever it needs it, saving you your weekly chore. Steam systems lose water faster than hot water systems, so the valve will be helpful. The granite countertops in my condo kitchen have a number of uncaulked seams, including a large one between the granite backsplash and the top. How can I fill them, and can I do it myself? CINDY, Somerville Yes, you can do it yourself. Go to a granite counter top installer and ask what kind of caulking to use. If that doesn't work, buy a clear silicone caulking compound, and make sure it is water-based. Such caulkings usually come in a cartridge, so you will need a caulking gun. Both are sold in hardware stores. How to do it: Press a bead of caulking into the seam; if it is as deep as the granite is thick , you will be putting in a lot. Do this until it oozes out of the seam, then wet your finger and smooth it off, and wipe off any caulking that gets on the face of the granite with a wet cloth. Keep a glass of water handy for wetting your finger. 