How Does Bed Bug Spray Work

How Bug Spray Works

Bugs have us outnumbered. By a lot. They swarm through our backyards, scamper through our houses — even crawl across our skin. According to the Smithsonian Institute, there are more than 200 million insects for every human on the planet, and one soil sample study in Pennsylvania found 425 million insects in a single acre. With numbers like those, we can’t hope to eradicate bugs, and with the huge and vital role they play in our ecosystem, we wouldn’t want to. But sometimes we want to keep them away from us. Preferably far, far away. That’s where bug spray comes in.

Bug sprays generally fall into two broad categories:insecticidesandrepellents. The U.S. Environmental Protection Agency (EPA) classifies both insecticides and repellents aspesticides, but while insecticides are designed to kill insects on the spot or reduce their numbers over time by disrupting their ability to reproduce, repellents work by making us less attractive to bugs, keeping them away from us.

Most of the bug sprays we use on our bodies act as repellents, while the products we use to keep six-legged pests out of our homes may be either repellents or insecticides. Some bug sprays are effective against just about anything they come into contact with (unfortunately this also includes birds, fish, and small mammals), while others work only on certain insect species. Farmers, resort communities and even military outfits often use insecticide sprays to control bug populations across large areas, but in this article we’ll focus on the kinds of bug sprays we use around our homes and on our skin.

Whether you need to rid your kitchen floor of ants or keep mosquitoes from ruining your camping trip, you’ll find any number of options on supermarket shelves, but the active ingredients listed on each label are enough to make you wish you paid more attention in chemistry class. So, what are all those ingredients, and what do they do?

How long does it take for commercial sprays to kill bedbugs?

This is a pretty vague question, so I’ll give the best estimates that I can. First, sprays are broken down into two categories: contact sprays kill right away and then evaporate, while residual sprays work more slowly but last a long time. The actual time it takes to kill bed bugs will depend on which type of spray you’re using, as well as on the active ingredients in that spray.

Most contact sprays will kill bed bugs in just seconds. This is assuming that the bug isn’t from a strain that is resistant to the active ingredient that your spray uses. This is a growing problem, so make sure that you’re using professional-strength chemicals with the latest formulas. Avoid grocery store brands at all costs; these are often using outdated formulas.

Residual sprays won’t kill bed bugs immediately, as they’re meant to be laid down in a perimeter and kill bed bugs that pass through the area over a long period of time. Depending on the individual spray, and the conditions of where it was used, a residual insecticide could be effective for anywhere from two weeks to over a year. The time from exposure to death will also vary – some sprays can kill exposed bed bugs in under a minute, while others take several minutes to work.

How Bug Spray Works

Insecticides: The Big Guns

Have you ever wondered why there are so many different types of bug sprays for the pests in and around our homes — one for wasps and hornets, one for ants and roaches, and still another for fleas and ticks? As it turns out, they contain very similar insecticides, although their specific ingredients and formulations differ depending on how and where the sprays will be used.

Most household bug sprays contain one or more insecticides in thepyrethroidfamily. Pyrethroids are synthetic chemicals designed to mimic the natural oils found in chrysanthemum flowers [source: National Pesticide Information Center]. They affect an insect’s central and peripheral nervous systems on contact, causing tremors, paralysis and a quick death [sources: EPA, NPIC]. Pyrethroids are effective against all sorts of insects, including beneficial bugs like bees and butterflies. They’re also highly toxic to fish.

Pyrethroids such aspermethrin,prallethrinandcypermethrinare the active ingredients in many wasp and hornet sprays. If you’ve ever had to deal with a nest in your yard, you know that it’s best to spray in the evening, when these insects are less active. This is partly so they won’t dive-bomb your head as you attempt to wipe out their home and family, but it’s also for efficiency, since the spray is likely to instantly terminate any wasps that are in the nest.

Pyrethroids are also found in sprays targeting ants, roaches, silverfish and other crawling critters. Since it’s not always easy to find the source of an ant or roach invasion, these sprays need to work over an extended time to effectively kill insects outside their nests. For this reason, ant and roach sprays usually containpiperonyl butoxide, an additive that prevents the insecticide ingredients from degrading before they can work [source: NP IC]. These sprays are applied along walls, doorways and insect trails, and the bugs are killed when they ingest or crawl over the residue.

Household flea and tick sprays use pyrethroids to kill adult fleas and ticks, piperonyl butoxide to extend the life of the insecticide ingredients, and a growth inhibitor likepyriproxifento prevent new eggs and larvae from developing [sources: Doctors Foster and Smith, NP IC].

Commercial farmers and backyard gardeners have long relied on a class of insecticides known asneonicotinoidsfor their effectiveness against aphids, beetles and other plant-eating pests. Unfortunately, these neurotoxic liquids and sprays have recently been linked with colony collapse disorder and the decline in the population of honeybees and other pollinators. To help protect bees, check the labels at your local garden center: Products containing neonicotinoids are now required to have a "bee advisory box" on the label [sources: EPA, Texas A&M AgriLife Extension].

How Do Bug Sprays (Like Raid and Baygon) Kill Cockroaches?

Contrary to popular belief, cockroaches cannot survive a nuclear explosion; however, it is true that cockroaches are more tolerant to certain ionizing radiation than humans. Even so, they cannot survive bug spray, as it consists of certain neurotoxic substances – chemicals that mess with their nervous system and subsequently cause death.

Cockroaches are pretty amazing creatures. People who cringe at the sight of these little insects or find them disgusting may not have the same opinion, but if you look at the feats that cockroaches are capable of achieving, you would agree too… probably.

A cockroach can hold its breath for almost 40 minutes, and can therefore survive being submerged in water. It can live without water for a few days, without food for a month, and can even survive without its head for a few weeks!

Furthermore, there’s a common belief in popular culture that cockroaches can survive a nuclear explosion (which, by the way, they can’t). However, one thing cockroaches seem unable to survive is bug spray. The likes of Raid, Hit etc. are often fatal to these roaches, but what’s so special about these insecticides that they are able to kill such tough and durable insects so quickly?

Before we get to that, let’s first examine the most popular belief pertaining to cockroaches.

Can cockroaches survive a nuclear explosion?

No, cockroaches can’t survive a nuclear explosion.

Sorry to burst the bubble of all those cockroach lovers out there, but the idea that they could survive a nuke isn’t true. The energy and heat generated as a result of a nuclear explosion are simply too much for any living thing to withstand, and cockroaches are no exception.

Cockroaches might not be able to survive a full-scale nuclear explosion, but they ‘can’ certainly tolerate ionizing radiation longer than we humans can do.

This is due to the way radiation harms things. Humans and other creatures are most vulnerable to DNA damage (caused by radiation poisoning) when their cells are dividing. Since cells all over our bodies are dividing throughout our lives at all times, we are always at a high risk for radiation poisoning.

Radiation therapy, a commonly employed and effective part of cancer treatment, actually works by damaging the DNA of cancerous tissue present in the patient’s body. (Photo Credit :

Roaches, on other hand, are anatomically different. Their cells only divide when they are molting – a process through which a critter routinely casts off a part of its body. The thing is that cockroaches only molt once every few weeks, so they are at a much lower risk of being harmed by radiation than humans. You can read more about cockroaches’ ability to tolerate radiation better than humans in this article: Can Cockroaches Really Survive A Nuclear Explosion?

If cockroaches can withstand harmful radiation, why can’t they tolerate bug spray?

Cockroaches can handle more radiation than humans, but they can’t survive even a little bug spray because radiation poisoning and chemical poisoning are two very different things, attacking the subject in significantly distinct ways.

Although the constituents of individual bug sprays may differ, most ‘roach killer’ sprays contain pyrethroids – fast-acting organic compounds found in the majority of household insecticides and insect repellants.

The reason behind their popularity as an ingredient in bug spray is that they are axonic toxins, which means that if used on roaches, pyrethroids paralyze them by preventing the function of voltage-gated sodium channels in roaches’ axonal membranes.

A bug spray. Notice the composition printed on its cover.

Another reason pyrethroids are a popular choice for bug sprays is that a very small dose of pyrethroids can kill roaches, which is why the sprays are generally harmless to humans (i.e., their concentration in bug sprays is quite low). However, they may harm sensitive individuals or aquatic creatures (like fish) if applied directly to water, as they dissolve very poorly.

Some commonly used pyrethroids include allethrin, tetramethrin, resmethrin, cyfluthrin, permethrin and esfenvalerate. Also known as ‘first-generation pyrethroids’, these were primarily developed in the 1960s.

The structural formula of Allethrin, a synthetic pyrethroid commonly found in bug sprays.

In a nutshell, a cockroach may be able to survive radiation, but it certainly can’t survive a nuclear explosion, nor a deadly shot from a pyrethroid-rich bug spray.

How Does Bug Spray Work? Surprisingly Easy Yet Effective

What are the benefits of insect repellents and insecticides? How does bug spray work and is it safe to use?

Bugs, which is a general term that refer to different types of insects, are a nuisance to gardeners. They are what we call as pests that destroy the health and jeopardize the growth of plants. It’s vital to prevent their infestation, or else the hard work and money invested in the garden become useless in just a few bites. And the best solution to this is the application of bug spray, considered as pesticides.

How does bug spray work exactly? First and foremost, bug sprays have two categories, which are repellents and insecticides. Whether you prefer insecticides or repellents, both are a type of bug spray that’s designed to specifically ward off insects. These are normally used at homes and in gardens. Although the main objective is to eradicate bugs or insects, repellents and insecticides have differences.

Insect Repellents

As far as repellent is concerned, how does bug spray work? It doesn’t directly kill insects but rather fend them off from making a contact on skin. In a simpler word, this kind of pesticide is worn on skin or clothes, which makes the bugs less interested in reaching out near you. But we’re actually talking about bug spray for garden use, right? Well, there are repellents that you can spray on plants and work the same way like on skin by eliminating the infestation of insects.

Insect repellents are either synthetic or natural. They do not only repel bugs, but also highly prevent the development of infectious diseases on humans and animals. But some brands can do more harm than good to the health. There are bug sprays that are made of GMO, N-diethyl-3-methylbenzamide which is most commonly known as DEET and other hazardous chemicals. These should be absolutely banned to use because although they effectively eliminate insects they can cause physical conditions in the long run.

Repellents that contain deet protect plants much longer, which is why some gardeners are still dependent on this type of bug spray. It can ward off insects for 5 hours. Those naturally mixed solutions work in a shorter period of time. But remember that it’s not only for plant protection that you have to consider but also health concerns. Thus, it’s best to choose an insect repellent, regardless of how does bug spray work on plants, that is one of the stuff approved and registered by the U.S. Environmental Protection Agency or EPA.


For insecticides, how does bug spray work and is it safer than repellent as far as health is concerned? This other type of pesticide effectively works in preventing bugs on plants by directly killing them on the spot. It also helps disrupt their ability to produce eggs. In a more sense, it seems more beneficial to use because they help eradicate a huge number of bugs in the garden.

How does bug spray work with phrethroid? Pyrethroids, which include cypermethrin, permethrin and prallethrin, are a common chemical ingredient in insecticides that act similarly as the natural oils in chrysanthemum, which also naturally wards off bugs. This chemical instantly kills insects by affecting the peripheral and central nervous systems that result to paralysis, tremors and eventually death in seconds. Based on this scientific explanation, it is a very effective tool to use for gardeners.

However, one of the downsides of using this is that they can also eradicate bees and other pollinators. If in case this is the best choice for you, make sure to spray only on a very early morning, late afternoon or evening as these are the times where bees are not present.

Organic Bug Spray

So the next question to answer apart from how does bug spray work and how safe it is to use is if there are natural DIY solutions you can use? Of coruse, there are organic recipes that are a great alternative. This is most recommended because they effectively eliminate bugs while keep humans and animals safe from side effects due to absence of chemicals and other harmful ingredients.

1. Garlic Oil Spray

  • 3 to 4 cloves of garlic – minced
  • 2 teaspoons of oil
  • ​1 teaspoon of dish soap or liquid
  • 1 pint water

Simply mix garlic and oil, and let it sit overnight or 6 to 8 hours. Strain the garlic and throw away. Pour the oil to the water and add dish soap. Refill an empty spray bottle with this solution and shake once before using to your plants.

2. Hot Pepper Spray

  • 2 tablespoons hot pepper sauce
  • Drops of dish soap or liquid
  • 1 quart water

Mix the hot pepper and dish soap in water. Let it sit for hours or overnight. Pour the solution in a bottle spray and use whenever needed.

We can conclude how does bug spray work on plants is very effective. But let’s not also forget that the ingredients should be considered always since we should not only focus on the elimination of insects but also protect our health.

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