How Do Insecticides Work? 

If you discover an insect infestation in your home, your first instinct is likely using some kind of bug spray to kill the roaming critters on contact. Ideally, you’ll then follow up with food cleanup and sealing off any areas the insects could have used to enter your home. But the first part of that process seems almost like magic; how exactly does a liquid spray instantly kill the bugs in your home? Do they all work the same? And do some have different ingredients than others? 

Conventional Bug Sprays 

Let’s start by talking about how conventional bug sprays work. The term “bug spray” is usually applied to one of two different types of products. The first category is insecticides, which are designed to immediately kill any insect that comes into contact with them. The second category is repellants, which are designed to be sprayed on your body or nearby areas to deter insects from approaching you. 

At the store, you’ve likely seen dozens of different insecticide options, each designed for a specific type of insect. But while the exact formulations and ingredients may differ, the active ingredients are mostly the same. Household bug sprays are usually reliant on chemicals in the pyrethroid family; these are synthetic chemicals that mimic the function of oils in chrysanthemum flowers. They happen to interfere with the nervous systems of insects, working as a kind of “signal jammer” that prevents the insect from functioning normally. Usually, when the insect comes in contact with this material (either topically or by ingesting it), they begin to spasm, become paralyzed, and ultimately die quickly. 

Different types of insecticides may also have additional ingredients. For example, ant and roach sprays often feature piperonyl butoxide, which extends the operative lifespan of the bug spray; this allows them to be sprayed along trails and in nests, killing many species of insect over a long period of time. 

Repellants, by contrast, feature ingredients that are designed to be disgusting or confusing to insects, such as citronella oil or DEET (N,N-diethyl-meta-toluamide). Most commercially available skin-applied insect repellants have been formally approved by or registered with the EPA, and have been thoroughly evaluated for human safety. 

The Problem With Chemical Formulas

Conventional insecticides can be problematic, however. Certain insecticide ingredients, like cypermethrin (a pyrethoid compound) can cause tremors, writhing and convulsions in mice, rats, and other small pets. In humans, it can cause dizziness and itching. There are also environmental concerns; insecticides with harsh chemicals can be harmful to fish, birds, and other wildlife, and if they get into a water supply, they can be even more dangerous. 

Alternatives to Conventional Insecticides 

While insecticides with pyrethoid chemicals are highly effective in getting rid of the problem, it’s often better to choose an alternative means of pest control. 

For example, for a household insect problem, you could use: 

  • Natural bug spray. Natural types of bug spray, like Maggie’s Farm Simply Effective Home Bug Spray, rely on plant oil-based bug sprays to kill and repel insects, spiders, ants, roaches and more. This example uses a water-based formula with simple ingredients like thyme oil and rosemary oil to kill insects on contact. Once applied, it repels future insects with a natural deterrent effect. 
  • Traps and bait gels. You can also find household products designed to trap insects, enclosing them and preventing them from escaping, or “bait” products that attract insects and prompt them to carry poisonous materials back to their nests. These products vary in composition and effectiveness, but are often safer than chemical-based bug sprays because they’re much better contained. 
  • Cleanup and prevention. The best approach may be to alter your household to prevent the insect problem from getting worse or recurring. For example, you can start by giving the effected room a thorough cleaning from top to bottom, getting rid of any sticky spots, crumbs, or other materials that might serve as an attractive element. From there, you can patrol the inside and outside of your home, and seal up any holes the insects are using to get inside. 
  • Professional exterminators. It’s also worth noting that some insect problems are too big or too complex for any simple household product to handle. If you have a terrifying insect infestation, or one that’s interfering with the structural integrity of your home, it’s often better to call a professional exterminator. 

Most bug sprays are effective because they rely on a chemical formula that prevents an insect’s nervous system from functioning properly. However, these types of bug sprays can be harmful to you, your pets, and the environment. Instead, it’s often better to invest in a series of alternative solutions, like cleaning the affected area, placing traps, and investing in a bug spray with natural, safer ingredients.