A dehumidifier isn’t an effective standalone treatment for bed bugs. Bed bugs are unusually resistant to water loss, and lowering normal household humidity doesn’t reproduce the conditions used in experiments that found faster mortality under extremely dry, heated conditions. Humidity can influence bed bug survival, but temperature changes that relationship substantially. Recent research found that dry conditions increased mortality when bed bugs were already exposed to unusually high temperatures. That is very different from showing that a household dehumidifier can eliminate an infestation.
What Research Shows About Humidity and Bed Bug Survival
A 2025 study exposed adult male bed bugs to three relative humidity levels, 10%, 45%, and 90%, across temperatures ranging from 25°C to 40°C (77°F to 104°F). The experiments lasted up to 14 days.
At 37°C (98.6°F), median survival exceeded 14 days at 45% and 90% relative humidity. Reducing humidity to 10% shortened median survival to 12 days. At 39°C (102.2°F), survival under the driest condition fell to approximately four to six days.
Those temperatures are much hotter than an ordinary occupied room.
At 40°C (104°F), mortality increased substantially across all three humidity levels. Interestingly, the shortest survival occurred at 90% relative humidity, where the study recorded a survival time of one day. The researchers concluded that dry conditions generally intensified thermal stress, but the interaction between temperature and humidity wasn’t simply a case of lower humidity always producing faster mortality.
A Dehumidifier Doesn’t Reproduce Those Conditions
The experimental results shouldn’t be interpreted as evidence that lowering a normal room from moderate humidity to a comfortable dry level will eliminate bed bugs.
The strongest low-humidity effects occurred at 37–40°C and 10% relative humidity. A household dehumidifier isn’t designed to turn an occupied room into that experimental environment.
The study also used adult male bed bugs under controlled laboratory conditions. It didn’t test entire household infestations containing eggs, nymphs, fed and unfed adults hidden throughout furniture and structural cracks.
For those reasons, there isn’t an evidence-based household humidity percentage that can be recommended as a bed bug treatment.
Bed Bugs Are Highly Resistant to Dry Conditions
Bed bug biology also works against the idea of simply drying them out.
Earlier research found that bed bugs have a very low rate of water loss and can tolerate losing roughly 30–40% of their body water. Adult bed bugs in that study could survive for two weeks at effectively 0% relative humidity without access to food or water.
Bed bugs also don’t depend on absorbing ordinary atmospheric moisture. Researchers found that they replenish their water primarily through blood feeding and lack the ability to absorb water vapor under the conditions tested.
Dry air can increase water loss, but bed bugs have several adaptations that allow them to withstand desiccation surprisingly well.
Clustering Helps Bed Bugs Conserve Water
Bed bugs commonly aggregate together in harborages, and that behavior can improve their resistance to dehydration.
Research found that aggregation creates a water-conserving group effect. Quiescence, or remaining relatively inactive, also reduces water loss. First-instar nymphs were more vulnerable to water stress than later stages because they contained more water and lost it more rapidly.
This is another reason laboratory survival figures shouldn’t be converted directly into a prediction such as “running a dehumidifier for two weeks will kill the infestation.”
Could Lower Humidity Help Desiccant Dusts?
Humidity can affect some insecticide dusts, but this requires a more careful distinction than simply saying a dehumidifier makes diatomaceous earth work better.
A study examining moisture and bed bug insecticide dusts found that exposure to steam significantly reduced the performance of the products tested. Long-term aging under elevated humidity also reduced the effectiveness of CimeXa, a silica-gel desiccant dust.
That establishes that moisture can influence desiccant-dust performance. It doesn’t establish that running a household dehumidifier alongside diatomaceous earth for bed bugs produces meaningfully better control in an infested home.
If you’re using a registered desiccant pesticide, apply and maintain it according to its label rather than trying to optimize it with an untested humidity target.
Heat and Humidity Shouldn’t Become a DIY Treatment
The temperature-humidity study shouldn’t be treated as instructions for recreating lethal conditions with heaters, humidifiers, or dehumidifiers.
Professional bed bug heat treatment depends on bringing infested materials and harborages to lethal temperatures while monitoring conditions throughout the treated space. Raising the air temperature in one part of a room doesn’t prove that the same temperature has reached bugs hidden inside furniture, walls, or other insulated locations.
If heat is being considered as a treatment, how heat kills bed bugs is more relevant than trying to reproduce an experimental temperature-humidity combination with household appliances.
Questions About Dehumidifiers and Bed Bugs
Will lowering my home’s humidity prevent bed bugs?
There isn’t good evidence that maintaining a particular household humidity prevents a bed bug infestation. Bed bugs are primarily introduced into homes by being transported from an infested location, so humidity control isn’t a substitute for established prevention and monitoring measures.
What humidity level kills bed bugs?
There isn’t a practical household humidity level that can be recommended for killing bed bugs. Adult bed bugs have survived extremely dry laboratory conditions for extended periods, and the effects of humidity also change with temperature.
Will a dehumidifier make diatomaceous earth work better?
Moisture can reduce the performance of some insecticide dusts, but that doesn’t establish that adding a dehumidifier improves a bed bug treatment. Use only appropriately registered and labeled pesticide dusts and follow their application instructions.
Should I combine a dehumidifier with a space heater?
No DIY temperature-humidity combination from the laboratory research should be treated as a household treatment protocol. Improvised whole-room heating can create fire, electrical, and heat-related hazards while leaving cooler harborages where bed bugs survive.