Salt does not kill bed bugs in any practical sense. Unlike softer-bodied pests like slugs, bed bugs have a waxy outer shell that prevents salt crystals from drawing moisture out of their bodies. Sprinkling table salt around your bed or furniture will not dehydrate, repel, or eliminate a bed bug infestation.
Why Salt Doesn’t Work on Bed Bugs
The idea behind using salt as a pest killer comes from how it works on slugs and snails. Salt pulls water through their permeable skin through a process called osmosis, effectively drying them out. Bed bugs, however, have a hard exoskeleton coated in a thin layer of wax. Salt crystals sitting on a surface simply can’t penetrate that shell, so no dehydration occurs. The bugs walk right over it.
Saltwater sprays don’t solve this problem either. Spraying a salt solution into cracks and crevices where bed bugs hide may irritate them slightly, but it won’t kill them. The water evaporates, leaving behind salt residue that the bugs ignore. Epsom salt (a magnesium and sulfate mineral, not true salt) dissolves more easily in water than table salt, which might seem like it would improve penetration. It doesn’t. Epsom salt also fails to get past the exoskeleton.
What About Hot Salt Water?
One study from a nursing college in India found that treating beds with hot salt water reduced bed bug density by over 90% across a four-week period. That sounds promising until you consider what’s actually doing the work. Bed bugs are highly sensitive to heat. They die after 90 minutes of constant exposure to 113°F, or within 20 minutes at 118°F. Eggs are tougher, requiring 118°F for a full 90 minutes to reach complete mortality.
In other words, the hot water in that study was likely responsible for the results, not the salt. Pouring or applying very hot water to surfaces where bed bugs live can kill them on contact, but it’s the temperature that matters. Adding salt to the water doesn’t make it meaningfully hotter or more lethal to bed bugs. And pouring hot water on mattresses and furniture creates its own set of problems, including damage and mold.
What Actually Kills Bed Bugs
Effective bed bug control relies on heat, physical barriers, targeted chemicals, or a combination of all three. No single method works perfectly on its own, which is why pest management professionals typically recommend an integrated approach.
Heat
Heat is one of the most reliable tools against bed bugs at every life stage. Running infested clothing, bedding, and fabric items through a clothes dryer on high heat kills bugs and eggs quickly. Professional heat treatments can raise the temperature of an entire room to lethal levels, reaching into cracks and hidden spaces where bugs nest. Trying to replicate this at home with a thermostat or space heater is both ineffective and dangerous.
For smaller items, sealing them in black plastic bags and leaving them in a hot car on a sunny day can work, though success depends heavily on climate. The internal temperature needs to stay above 118°F for a sustained period.
Cold
Freezing can also kill bed bugs, but only if your freezer reaches 0°F and items stay sealed inside for at least three days. Many home freezers don’t actually get that cold, so check with a thermometer before relying on this method.
Desiccants
If the idea of drying bed bugs out appeals to you, there is a product that actually accomplishes this: diatomaceous earth, registered as a pesticide. Unlike salt, the microscopic particles in pesticide-grade diatomaceous earth scratch through the waxy coating on a bed bug’s exoskeleton, causing them to lose moisture and die. The catch is that it works slowly, sometimes taking several months. Bed bugs also can’t develop resistance to it, which gives it an advantage over chemical sprays. Use only the EPA-registered pesticide version. Pool-grade or food-grade diatomaceous earth has differently sized particles that pose a serious inhalation risk.
Physical Barriers and Cleaning
Encasing your mattress and box spring in sealed protective covers traps any bed bugs inside, where they eventually starve. Interceptor traps placed under furniture legs catch bugs trying to climb up to reach you while you sleep. Regular vacuuming helps reduce their numbers, though you should seal and dispose of the vacuum bag in an outdoor trash container immediately after each use.
Chemical Treatments
EPA-registered pesticides labeled for bed bugs are another option, though they work best as part of a broader plan. Foggers (bug bombs) are generally a poor choice. The spray can’t reach the tight cracks where bed bugs hide, and improper use creates fire and health hazards. Targeted sprays applied directly into harborage areas are more effective.
Why DIY Methods Often Fail
Bed bugs are notoriously difficult to eliminate because they’re small, flat enough to hide in seams and crevices the width of a credit card, and capable of surviving months without feeding. A single pregnant female left behind after treatment can restart an infestation. Home remedies like salt, baking soda, and essential oils circulate online because people understandably want a cheap, fast fix. The problem is that bed bugs evolved to resist desiccation. Their waxy exoskeleton exists precisely to keep moisture in, and household substances simply aren’t designed to breach it.
If you’re dealing with more than a handful of bugs, professional treatment offers the highest success rate. Professionals can apply heat evenly throughout a room, use targeted chemicals in the right concentrations, and monitor for re-emergence over weeks. For lighter infestations caught early, a disciplined combination of high-heat laundering, vacuuming, encasements, and interceptor traps can bring things under control, but it requires consistency over several weeks, not a one-time application of any single product.