Professional pest control companies use a combination of chemical insecticides, baits, dusts, growth regulators, and physical methods depending on the pest. The specific products vary by situation, but most treatments fall into a handful of well-established chemical classes that target insects, rodents, or other pests in different ways.
Pyrethroids: The Most Common Spray Treatment
The backbone of most professional pest control is a class of chemicals called pyrethroids. These are synthetic versions of pyrethrins, a natural insecticide extracted from chrysanthemum flowers that has been used for over a century. Common active ingredients include bifenthrin, permethrin, deltamethrin, cypermethrin, and lambda-cyhalothrin. You’ll find these in the liquid sprays technicians apply around baseboards, door frames, window sills, and exterior perimeters.
Pyrethroids work by jamming open the nerve cells of insects, causing uncontrolled nerve firing that leads to tremors, paralysis, and death. They act fast on contact, which is why they’re favored for general pest treatments targeting ants, spiders, roaches, and other crawling insects. For the homeowner, the practical takeaway is that these sprays dry into a residual barrier that continues killing insects for weeks after application.
Gel Baits for Cockroaches and Ants
For cockroach and ant infestations, professionals rely heavily on gel baits rather than broadcast spraying. These are applied as small dots or lines in cracks, crevices, under appliances, and inside wall voids. A leading commercial product like Advion Trio combines three active ingredients: one that kills on ingestion plus two insect growth regulators that prevent nymphs from molting into adults. This multi-pronged approach is designed to wipe out both the roaches you see and the young ones developing out of sight.
Gel baits are preferred over sprays for cockroaches because roaches carry the bait back to harborage areas, spreading the toxin to others in the colony. Spraying near bait stations can actually be counterproductive, since residual sprays may repel roaches away from the bait.
Insect Growth Regulators
Insect growth regulators, or IGRs, are a class of chemicals that don’t kill adult insects directly. Instead, they disrupt development. Professionals use two main types. The first mimics juvenile hormone, a natural chemical that controls when immature insects transition to adulthood. Active ingredients like hydroprene, methoprene, and pyriproxyfen keep insects stuck in immature stages, preventing them from reproducing. The second type, chitin synthesis inhibitors like diflubenzuron and novaluron, blocks the formation of new exoskeletons. Without the ability to molt, developing insects die.
IGRs are commonly paired with conventional insecticides for flea treatments, cockroach control, and termite baiting systems. They’re a long-game tool: they won’t give you instant results, but they collapse pest populations over time by eliminating the next generation.
Termite Treatments: Liquid Barriers and Bait Stations
Termite control is its own specialty, and companies typically offer two approaches. Liquid treatments involve trenching around the foundation and injecting a termiticide into the soil to create a continuous chemical barrier. The most widely used active ingredient is fipronil (sold commercially as Termidor), which works differently from pyrethroids. Termites that contact fipronil carry it back to the colony and spread it through normal grooming and feeding behavior, creating a chain reaction. Other liquid options include imidacloprid (a neonicotinoid) and chlorantraniliprole.
The second approach uses in-ground bait stations installed around the perimeter of the home. Systems like Sentricon use noviflumuron, a chitin synthesis inhibitor that prevents termites from molting. Trelona stations contain novaluron, and Exterra stations use diflubenzuron. All of these work the same basic way: worker termites feed on the bait and share it with the colony, gradually eliminating the entire population. Newer versions of Sentricon come pre-loaded with bait so there’s no waiting period for termites to find empty monitoring stations first.
Bed Bug Treatments: Heat and Desiccants
Bed bugs have developed resistance to many conventional insecticides, so professional treatment has shifted toward heat and desiccant dusts. During a heat treatment, technicians bring industrial heaters into the home and raise the ambient temperature to around 135°F. The target is getting every crack, crevice, and wall junction to at least 122°F, which is the thermal death point for bed bug eggs (adults and nymphs die at 118°F). Heaters typically run for four to five hours once peak temperature is reached.
For lasting protection after a heat treatment, many professionals apply silica aerogel dust or diatomaceous earth into wall voids, behind outlets, and along crevices. These desiccant dusts work by stripping away the waxy coating on a bed bug’s body, causing it to dry out and die. They’re non-toxic to humans and pets, and they remain effective for months or even years as long as they stay dry and undisturbed.
Neonicotinoids
Neonicotinoids are synthetic chemicals modeled after nicotine. Common active ingredients include imidacloprid, dinotefuran, thiamethoxam, clothianidin, and acetamiprid. They work by binding to nerve receptors for far longer than the insect’s own signaling chemicals do, overstimulating the nervous system until the insect dies. In structural pest control, neonicotinoids show up in termite treatments, ant gels, and some perimeter sprays. They’re particularly useful for pests that live in soil or wall voids because they’re effective at low concentrations and have long residual activity.
Rodent Control
For mice and rats, pest control companies use a combination of exclusion, traps, and rodenticides. Exclusion comes first: sealing entry points with steel wool, caulk, or metal flashing to block access. Snap traps and multi-catch traps are standard tools, placed along walls and runways where rodents travel.
When rodenticides are used, they typically fall into three categories. Anticoagulant baits (based on warfarin and related compounds) prevent blood from clotting, causing internal bleeding over several days. Bromethalin is a neurotoxin that causes brain swelling. Zinc phosphide produces toxic gas in the stomach after ingestion. Professional applicators place these in tamper-resistant bait stations that children and pets can’t open. Most residential rodent jobs prioritize trapping and exclusion, with rodenticides reserved for severe infestations or outdoor use.
Application Equipment
Professional-grade equipment is a significant part of what separates commercial pest control from DIY efforts. Technicians use compressed-air sprayers and backpack sprayers for liquid treatments, applying diluted insecticide at low pressure to targeted surfaces. For dusts, they use bellows dusters and bulb dusters that puff fine particles into wall voids, electrical outlets, and other enclosed spaces where sprays can’t reach.
Crack-and-crevice injectors allow precise application of gels, foams, and aerosols into tight gaps. For termite work, sub-slab injection rigs pump liquid termiticide through the concrete foundation. Heat treatment setups for bed bugs involve industrial electric or propane heaters, fans to circulate hot air, and temperature sensors placed throughout the room to ensure every surface reaches lethal temperatures.
Green and Botanical Options
Many pest control companies now offer “green” or low-toxicity service lines. These typically rely on botanical insecticides derived from plant essential oils like peppermint, eucalyptus, and citronella. Peppermint oil has some effectiveness at deterring ants and spiders, while citronella discourages mosquitoes. These products break down quickly in the environment and pose minimal risk to people and pets, but they also provide shorter residual protection than synthetic chemicals.
Integrated pest management (IPM) programs take a broader approach, using chemical treatments as a last resort. IPM-focused companies emphasize sanitation, habitat modification, and physical exclusion first. Biological controls like Bacillus thuringiensis, a naturally occurring bacteria that produces proteins toxic to certain insects, are used in some commercial and agricultural settings. For residential pest control, though, “green” programs most often mean reduced-risk synthetic products applied in targeted ways rather than purely botanical formulations.
Re-Entry Times After Treatment
After an indoor spray treatment, most pest control companies ask you to stay out of treated areas for a minimum of four hours. The specific re-entry time depends on the product used and is listed on its label. For products classified as slightly toxic, the standard restricted entry interval is 24 hours. For moderately or very toxic products, it’s 48 hours, though these stronger formulations are rarely used in residential settings.
Technicians should post signs indicating what was applied and when it’s safe to return. Once the treated surfaces are dry, the risk of exposure drops significantly. If you have pets, fish tanks, or small children, let your technician know before treatment so they can adjust product selection and application methods accordingly.