Pest Elimination and Control Q&A

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Dear NH,

I have heard that ladybugs can sometimes do as much damage as termites. I fear I may have a problem. I live in Northeast Pennsylvania. We have a 1930 Cape Cod. Where can I find their nest and how can I get rid of them?



I have never heard of ladybugs doing any damage to homes at all. They are not capable of eating or chewing wood... they are mostly carnivores (with a few vegetarians thrown in). Your dog or cat may be at greater risk than your house... just kidding! Furthermore, ladybugs are a valued ally in the battle against other types of insects, such as aphids, which cause extensive damage to favorable shrubs and plants.

Ladybugs are known to hibernate in buildings during the winter and to sometimes emerge during warm spells. In fact, my own church swarms with them at times during the fall and Indian summer. They are more common in older buildings that have more access points due to the looser construction of the cheap energy days.

If you are still concerned, or even if you just find them to be a nuisance, a licensed exterminator worth his salt should be able to eliminate them. He probably won't really look for the "nest"... he will "shotgun" treat the affected wall with the appropriate chemical.


Dear NH,

When I moved into this house over 3 years ago, squirrels already lived here. It's an old house (1929) in an old neighborhood with lots of trees. There is a family of them living in an eave on the corner of the house where they have a hole made so they can come and go from outside. This eave is open to my attic on the inside and I hear them sometimes scooting about up there. There's holes around the underside of the eaves in other places, too, where they can get in and out of the attic.

Everybody I mention my squirrels to says they will do great damage, but so far they haven't done any more damage than it takes to make a nest in the eave... at least as far as I can tell. They have NOT eaten my wiring and burned down the house.

At one point, hearing horror stories of squirrel damage, I got alarmed enough to call my pest control service about them. They told me they didn't do squirrels. I called the city. The city told me that it was against the law to kill, molest, or otherwise harm the squirrels. Huh? They couldn't say why.

Should I be worried for the safety of my home and by extension, myself? An animal rescue lady told me I could run them off by tossing a few moth balls around in the attic, but I haven't done it. I did buy some mothballs, but I couldn't bring myself to take the next step. After all, they were here first.

So the squirrels remain. I say hello when I come home from work and they seem to tolerate me well enough, even though I couldn't say they're friendly. What are your thoughts on this matter?

CW from Jacksonville, FL.


I have known many folks who feel the way you do, and don't want to see harm come to small animals.

The problem is that the opening they use to enter your home will also allow access to bats and insects that are not as benign. And their droppings are accumulating... unless the former owner installed flush toilets for them.  This increases the potential for human disease and allergic reactions.

So I vote that you whip out the moth balls... it will not hurt them, because they will not eat them... or get some large humane traps and take them out of your attic. There is no need to harm them to evict them. Then you can repair the damage and seal the access hole.

Just remember... the longer you wait, the more incremental damage they will do, and the more expensive it and difficult it will be to get them out.

Dear NH,

My basement has a hole around the main water pipe, created by mice, that leaks whenever it rains. I would appreciate it if you could tell me how to fix this problem and whether a novice handyman w/ few tools can handle it. This basement happens to be a finished one. Thanks again.


Dear NM,

A good and easy way to seal a small leak like this would be to inject some expanding plastic foam into the area around the pipe. You can purchase this product in any hardware store. There are two types available… latex-based and solvent-based. Use the solvent-based type… the latex-based is not recommended for use below ground level.

Clean (as best you can) dirt and dust from the pipe and the cement before using this product. And don't overapply it. It will expand to fill the crack. Of course, any excess that expands into your living space can be cut off with a sharp knife once set.

Mice usually will not eat this stuff, but I can't guarantee they won't bore right through it. One thing you might do is to first push a small amount of steel wool through the hole as a "backer" to discourage gnawing... then inject the foam.

Dear NH,

We have pigeons that have staked out a corner of our house. They spend their time sitting under the eaves of the roof and making a mess on the ground underneath. Any advise for getting rid of them? FYI, this is an old four story house, so it is nearly impossible to reach their perch without a hook and ladder.

VG from Baltimore, MD


If you seriously can't get up to this area, you will have to accept the birdies as unwelcome borders! I know of no "long distance" extermination method except for shooting them that will solve your problem without. And I don't recommend shooting under these circumstances.

However most things are not as impossible as we think so if you can get up to the area, here are a few thoughts. If the eaves are hollows, you can install dark aluminum screen over the openings. This will keep all sorts of vermin out including bugs and bats. At your home's 4-story height the dark screening should be all but invisible to the eye. If a more finished look is desired the exposed edges of the screen can be covered with wood molding and then painted or stained.

If the eaves are just overhangs with a flat "perching" area, putting something up there that "moves" on contact will discourage all but the most persistent pigeons. You may, for example, use pieces of extruded aluminum gutter guard loosely nailed and positioned so that they are not seen from the ground. You can also use pieces of chicken wire, again loosely stapled or nailed and bent to make footing uncomfortable for the little dears.

There are more drastic methods involving chemicals. Poison bait is one method of bird control. Another method is the use of specially designed perches, which use a "wick" to apply a contact-type poison to the bird's feet. There are also chemicals that actually sterilize the birds leading to reduced populations. These methods are generally available only through a qualified and/or licensed exterminator. Though these methods may seem cruel, it is a fact that birds can carry various diseases that are spread through their droppings. Many bird control methods were developed to help the food industry protect its product… our food… from bird contamination. Given the fact that there are nearly a hundred types of potentially dangerous bacteria and parasites carried by birds in the wild, that unattractive "poop" could indeed be carrying a deadly cargo.

Dear NH,

After moving into our new house in Florida in 1996, we were immediately invaded with almost microscopic Pharaoh ants. We are told that they live in the masonry; the house is constructed of concrete blocks with stucco.

The ants are controlled with a boric acid paste. But, we have found nothing to eradicate them. Do you have any information on this problem?



Pharaoh ants are notoriously difficult to exterminate, especially in Florida where they can live inside and outside. Insecticide sprays, while effective in the sort term, can cause Pharaoh ants to exhibit a unique behavior… they will divide their colony up into multiple nests when threatened, making extermination even more difficult!

From what I have read about the various treatments, the only truly effective solution is to use poison bait both inside AND outside your home. Poison bait is a combination of a food the ants like and a slow-acting poison that lets the ants live long enough for them to bring the poisoned food to their nest. NO other form of extermination or insecticide should be used when bait is also used or you may kill the ants before they complete their deadly task!

Poison bait is admittedly a less-than-speedy a solution compared with spraying insecticide, but you are more likely to get to all the nests by taking the "friendly" approach. Not friendly to the ants, mind you… friendly to your home's inside environment! Spraying insecticides inside should always be done sparingly and with care, if at all, and only in the most dire of situations.

Apparently this treatment can take up to one year to show complete results, since Pharaoh ants tend to make multiple nests, not just one like carpenter ants, making them difficult to eradicate. However, once the nests inside and outside the vicinity of your home are exterminated you should get at least some relief from their invasion!

Dear NH,

We built a new home last year and have ants in our house this house was built very tight with everything caulked, plastic, and taped. How are they coming in?



In my experience, once you begin seeing lots of ants in your home, they are not coming in... they ARE in! Carpenter ants do not eat wood for food as do termites... they just tunnel within it to make their home. And they have little reason to enter your home just for food... there's plenty outside! Visible ants within the home is a sure sign that there is a nest in the house... somewhere.

Carpenter ants usually start their nests in water-softened wood produced by leaks in roofs or siding, around windows or in unflashed areas adjacent to cement or concrete. I have even seen ants nesting in countertops where there has been a long-term leak around or behind a sink or faucet. In a new home, though, the culprit is often the use of lumber in construction that may have already been populated with ants. Depending on the time of year your house was built, it is possible that a small nest formed inside a piece of stacked lumber but was dormant or too small to notice. Then the ants would become active in the warmth of the summer and begin doing their ant thing... eating, tunneling and reproducing.

Though modern houses are sealed fairly tight, I would venture to say that there is no home immune to infestation from ants or various other pests. Mice, for example, can find the smallest chink in your home's armor and make a cozy nest. Remember... they have nothing but time and lots of motivation!

Dear NH,

The roaches here have gotta go away!! Help !! What can I do ? I keep a clean house, I don't let crumbs collect under the tables, I vacuum regularly, etc. Essentially, I don't put out the "Welcome Here Bugs Mat".

But, I can NOT use standard, oil-based roach sprays. I have two children with severe asthma, and those types of products send them both into asthmatic episodes. I have tons of those little roach baits and motels scattered here and there through out the kitchens and bathrooms; just like the boxed instructions say to do. But does that work? Not for us so far. In fact, it seems that the roaches are actually having a "party'' on this stuff but NOT dying.

Can I use some diatomaceous earth? I have heard it is used as an insecticide, but I have been hesitant to use it for fear of it causing asthma problems too...since it is such a fine powder.



Diatomaceous earth (DE) is a really effective indoor AND outdoor pesticide against many types of insects that does not contain dangerous chemicals. It is made from the fossilized remains of diatoms... a type of plankton... which were left behind in massive amounts after the ancient oceans receded. These almost microscopic particles have very sharp edges which cut the external membranes or exoskeletons of insects such as ants and roaches. These membranes are similar to our skin in that they keep moisture inside the insect, but unlike human skin are relatively fibrous and thin. Once cut, moisture escapes and the bugs dehydrate quickly, often dying within hours. Fortunately, we humans don't have to worry about contact with DE since our skin is not vulnerable due to its flexibility and thickness.

It is important to use the proper form of DE. All DE is heat treated and sifted based on its intended usage. The type that is used for swimming pools is, to my understanding, not very effective for insect control. Pool filter DE is also much finer and therefore dustier than the insecticide-type.

Be aware that some brands of insecticidal DE have added chemical insecticides as a "kicker" to extend DE's killing power to other insects, specifically for those with tougher, DE resistant shells. One bug killer often added is pyrethrin, a "natural" insecticide extracted from the flowers of the chrysanthemum plant. Pyrethrin, as you may know, is commonly used in flea control around the home and also approved for use on pets.

Another very effective chemical against crawling insects is boric acid.  They can't help but ingest it as they walk through it, and die soon after.  They can also track it back to their nests.  If you're curious, boric acid is also used as a fireproofing compound, in eyewashes and as a fertilizer.  It is not very toxic, falling somewhere between aspirin and table salt in toxicity.

I cannot tell you what the effect of DE or boric acid would be on your children's asthma.  Only your physician can tell you that. It is certainly true that either could probably hurt anyone if they breathed too much of it, as with any fine dust. The same can be said of sawdust, dust from insulation and even airborne sand!

In writing this response, I learned something that I was not aware of… that many people are actually allergic to cockroaches. This allergy can trigger asthma attacks in susceptible people. There is a great article on cockroaches and allergic reactions from the Asthma and Allergy Foundation. Search for "cockroach" to find the article.

Knowing that roaches can be contributing to your children's problem presents a dilemma and requires you to make a judgment. In the real world, there is always a cost vs.benefit in using anything. With your physician's guidance, you can determine just what this risk is and find a compromise to the benefit of your children. For example, by applying small quantities of DE in "out-of-the-way" places where the insects walk and hide, you should get some results with minimal dusting of this product. Though some companies recommend widespread use of the product throughout the home, taking a more conservative approach to application may meet your doctor's approval.

If you can't find the product locally, you can order it from many online sources. One website with extensive information on all sorts of pest control issues is the Biocontrol Network.

Dear NH,

I suspect we've got a dead rodent inside walls, behind a cabinet. What next? Cut through the drywall? Pry the cabinet apart? (no access from above or below -- concrete slab, too near outside wall to access from attic space) Can I drill holes to try to locate .... remains ... before I cut through the drywall? Or should I just go ahead and pull off a large enough piece to make sure I can get to it? Suggestions about getting rid of the smell? Great Site, BTW! Hugely helpful, and helpfully arranged!

MR from San Antonio, Texas


Thanks for the kind words!

Though it may seem insensitive to your plight and eagerness to get rid of that nasty smell, my suggestion is to just open the windows and let the smell disappear on its own. You can cause a lot of damage trying to find the little critter, and with no guarantees! There are too many places that the body could be! What wall do you rip apart first? Which cabinet?

The good news is that the odor will dissipate in a few days on its own as the creature desiccates. Living in a wooded area myself, my clients and I have had to relive your agony many times over the last 25 years, so we all "feel your pain". I think, though, that your pain will be greater if you spend many hours and dollars trying to find this thing with no sure hope of success.

Dear NH,

I'm a new subscriber, so this may not be the right forum for this question.....but like the rodent question in last month's newsletter. I have an unwelcome visitor. It's a gray squirrel, who had evidently built a home in one of the soffits of my four dormer 2 and a half story house when the roof was damaged. After replacing the roof, the squirrel clearly did not have the easy access he'd had previously, so he/she chewed a softball sized hole in the facing board right beneath the roof. After waiting to be sure there are no babes in the nest, I want to clean out the area and reseal it. Do you have any suggestions for making it more squirrel resistant, other than cutting back the lilac bushes he uses as the path to the bay window roof that has clearly been the staging area to the site, which I clearly will do?


Dear T.

Squirrels present a difficult problem because they are very persistent once they find a nesting location. From what I have seen, the only two ways to eliminate a problem squirrel are to either make the attic area totally inaccessible or to trap it and move it far enough away that it will not come back.

As far as sealing the attic, using a metal flashing outside the wood repair will keep those sharp teeth and those of its relatives from getting back into your attic. The flashing can be painted to match the siding or trim so that it is hardly noticeable.

Of course, moving the offending squirrel may still be necessary. A nesting squirrel becomes territorial and will do whatever it has to in order to return to its nest, even as far as eating through your attic in another spot! New squirrels, on the other hand, will not be motivated enough to eat through the patched area.

Dear NH,

In your response to the person (last months newsletter) who thought there was a dead rodent in their wall, you mentioned that the best thing to do is to wait it out. I had a similar experience. However, I was able to find the body in the attic above my daughters closet. That was 6 months ago and the smell is still in her closet. I have tried room extra strength deodorizers to no avail. I was just wondering how long you had to wait for the smell to go away in your experiences?


Dear DO,

I have rarely had the smell linger longer than 2 to 4 weeks... usually quite pungent at first but disappearing over time. I have been involved with this situation perhaps 20 times over the last 25 years, but I do by no means discount your personal experience. I know that there will be times where circumstances might cause a more lengthy stink. Larger animals, such as squirrels or raccoons, must be removed ASAP but they are usually easier to locate because they cannot get trapped in the smaller spaces mice can. Of course, raccoons stuck in chimneys are not that uncommon!

Perhaps you have had more than one mouse and/or the one you found was not the only cause of the odor. Mice make nests, so where there is one there are usually many.

As far as getting rid of the odor in the closet, I would remove all the clothing and launder them. Let the closet air out empty and see if this helps. If the closet has any dampness in it, it might explain the resilience of the odor. Using a small fan can speed the airing/drying process. Once thoroughly dry, a repainting the inside of the closet may also be helpful.