Your Place: Getting rid of those ants inside the dishwasher

Question: Just wondering if you might have any suggestions for me regarding ants running all over the inside of my dishwasher. It is on an exterior wall, and we have sprayed an ant-control compound outside. We have not had many ants inside the kitchen or the rest of the house, just the dishwasher. I have been pre-rinsing the dishes before putting them in. I run it about every other day.

Answer: There must be a food source somewhere - maybe behind the dishwasher or under the dishwasher, or perhaps the filter is dirty and needs to be cleaned. I've seen these suggestions: using white vinegar and 20-Mule Team Borax, or chlorine bleach, or taking a Q-tip with a little bit of insecticide around the lip, or stuffing foam underneath the kick plate. I'm sure that after today, I'll get a dozen more.

What I understand from pest-control experts is that an ant colony sends out scouts to look for food. When they find it, the scouts return to the nest, then the ants go marching two by two to their meal. What you need is something that does in ants - but not the environment or your pets - that the scouts can take back to the colony to infect the population.

I've had great luck for the last two years with Ortho's Home Defense, which I spray only outdoors, and only when and where I see a line of ants crawling up the usual routes into the house (from the ground, up the foundation wall, and underneath the siding). I usually spray once on the target area, and that's it.

Q: I know you have written articles on how to take care of a deck. I use a good stain on ours every year, and I keep getting what looks like white bleach spots. I scrub, but they come back. Is there something else I could be doing? Our deck is mostly shaded.

A: One manufacturer, responding to a question about its product, suggested that the stain was applied when the deck had water below the surface or dew above it that had not evaporated. The resulting white or milky spots were the result of oxygenation and would gradually disappear as the wood dried, but would reappear if wetness continued.

The same thing happens when you apply a deck sealer if the wood isn't dry, other experts say.

From your letter, and from the opinions I've gathered, it seems as if your shaded deck doesn't have time to fully dry, and that you probably apply the stain with moisture present. Trying to scrub the white spots just increases the moisture content, so they never go away.

Q: I live in a rowhouse in Northeast Philadelphia. Several years ago, I read about white roofs and how they can reduce the amount of heat in a rowhouse in the summer. There was even a plan to put them on the homes of poorer people with no air conditioning. This made so much sense to me, white instead of that black, hot tar stuff. I haven't heard anything lately, though. Do they work? Are they too expensive? Do they make the house colder in the winter? Do they last well? How do they compare to an aluminum or "rubber" roof?

A: For the best information on these roofs, contact the Energy Coordinating Agency of Philadelphia at 215-988-0929, which was in charge of the "cool roofs" program back in 2000. I wrote about a pilot program that would coat 100 roofs.

From what I understand, an application of the elastomeric coating would reduce the temperature of an asphalt roof baked by the sun by 60 degrees, and that would lower the temperature of the rooms below enough to make an air conditioner unnecessary. (The expense to older residents on fixed incomes was the concern.) The coating also would help reduce heat loss in the winter.

I think the agency's staff will tell you that an elastomeric roof coating is a good start, but that a whole-house approach to energy efficiency is needed.