Point of View
Believe it or not, most folks don't like to have scorpions in their house. I would love it. But every time I let them loose in my house, they just disappear! I attribute the recent surge in scorpion invasions to two things. The first and foremost is the movement of urbanites to suburban and semi-rural areas that encroach on natural habitats where scorpions are abundant. The second is decreased use of pesticides, not only in these suburban settings, but especially in rural, agricultural settings. Some types of scorpions love houses (those with an "errant" lifestyle are the principal offenders). There are plenty of places to hide, a stable living environment, and ample prey. You can't blame the scorpions for taking over your home. They are simply exploiting a prime environment. After all, you are invading their world. Any species of scorpion may be found indoors. In the U.S.A., however, the main home-invading scorpions are Centruroides vittatus and Centruroides exilicauda. In California, where Centruroides is not common, several species of Pseudouroctonus commonly enter homes. Scorpions do perform a service in the house by eating other arthropods such as crickets and cockroaches (sadly, they do not seem to be partial to ants and termites). True, they do pose a potential stinging threat, but in the U.S. at least, this threat is minimal. Still, some people (especially northerners who have no prior experience with scorpions) seem to have a major problem with sharing their home with scorpions. The heart of the problem can be summed up thusly: scorpions live in your area; you live in your area. The scorpions were there first, and they are not going to leave. If you won't leave, then you have two options: 1) learn to coexist, or 2) go to war. Option 1 is the simplest and most cost effective solution. People move out to the country to get closer to nature. Scorpions are part of the natural environment. Most are not dangerously harmful (none of those in the U.S. are dangerous enough to get worked up about). Their presence makes life interesting. The good they do far outweighs the harm. And if they make just one northerner turn tail and head back to wherever it is they came from, then it's all worth it. If you are not willing to share your place you'd better have your big guns and lots of money, because scorpions are notoriously difficult to eradicate. A three-pronged, integrated control strategy is required for repelling scorpions and preventing them from reinvading your tiny kingdom. You must use a combination of control methods. No single approach will solve the problem. Not all situations are amenable to this approach, so success may not be achievable in your particular scenario.
Alter the terrain of your area of operations (in this case, your home and yard), so that the scorpions are robbed of suitable hiding places and hunting grounds. Your home is your barrier. It must be properly constructed and maintained. Any cracks or openings anywhere on the structure can provide scorpions with easy access to your home. You should consult a professional for advice on how to have your home sealed. Large cracks, such as those around pipes and conduits that enter the home, can be sealed with a variety of materials. Openings that cannot be sealed, such as ventilation holes, can be covered with a fine-meshed screen. Foundation and attic openings are among the hardest to locate and seal, and propably provide the principle means of entry into your home. Crawlspace foundations, and those constructed of block or stone, provide excellent homes for scorpions. The inside of the house must be sealed, too. Baseboards, cabinets, light fixtures, plumbing openings, etc. should be thoroughly sealed. A clean, featureless yard serves as a demilitarized zone. You must remove all debris (wood, rocks, bricks, old appliances, etc.) and eliminate all landscaping. Trees, shrubs, rocks, bricks, and wooden railroad ties, make excellent scorpion habitats. Stone or block walls, and wooden fencing also make outstanding scorpion habitats. The degree to which you successfully carry out this cultural/mechanical portion of your control program will determine whether or not you win the war against scorpions. Successful cultural/mechanical control will help eliminate scorpions and will permanently keep them from reinvading your home.
Scorpions can be controlled with pesticides, but because of the scorpions' cryptic nature, it is difficult to deliver the pesticide directly. Residual pesticides, i.e., pesticides that last a long time after application, provide a means of "indirect fire" against the scorpions. Residual pesticides should be applied to the yard and exterior of the home, paying special attention to structures that provide harborage (stone walls, etc.) and potential entry points around the home. Pesticide application must be done on a regular basis, the interval of which will be determined by the severity of the infestation and the success of your cultural and mechanical control methods. This type of pesticide application can only be done by a certified pest control operator, so consult your local pest control company for more information. Although an important part of the overall control strategy, chemical control is the one most fraught with problems. It is expensive, temporary (needs to be repeated), and environmentally and medically hazardous. Do not try to do this yourself. The potential for unintended, serious outcomes is too great.
Finally, there's the dirty work. In order to achieve immediate results, scorpions currently living within the borders of your yard and home must be hunted down and terminated, with extreme prejudice. Search and destroy missions are conducted at night using portable blacklights and must be repeated for several weeks. Patrols scour the yard and home (room to room, if necessary), in search of scorpions. Any scorpions found must be captured and/or killed. Controlling scorpions by such "direct fire" is stressful, dangerous work, and should be conducted only by professionals. It would be nice if you could call a pest control company and have them do all these things for one fee. Unfortunately, very few pest controllers are aware of the proper way to control scorpions, and thus do not offer all of the services described here. So you will probably have to coordinate the work of several companies yourself in order to achieve control. Follow these procedures to the letter, and you will be able to control your scorpions (and pretty much all other bugs). Fail to properly execute any of the control methods, and you'll be living with scorpions for the foreseeable future. Good luck.