Heavy rainstorms can not only flood your garden, but also bring pests directly into your home.
When underground nests fill with water and outdoor hiding places are gone, insects and rodents seek dry, sheltered areas. Unfortunately, their haven is often a wall, basement, or kitchen.
“Rain creates two problems: displacement and opportunity,” says Ed Dorschun, vice president and technical director of Catchmaster, a pest control brand used by professionals for more than 70 years and sold in retail stores nationwide. When it rains, indoor pests will seek out dry ground. Some rely on the aftermath of rain for food, reproduction, and even shelter.
Your home is not defenseless. There are many strategies you can use to keep pests out of your home after a storm. Pest experts say they’re the most common pests that invade your home after the rain, and how to stop them.
Pests that tend to appear after rain
Pests such as ants and rodents can easily escape during storms and flee into your home in search of a dry, warm place. Other pests, such as mosquitoes and flies, breed in what rain leaves behind, such as standing water, wet debris, and damp garbage.
Ali
If you see them: hours after the storm
When it rains, ants are the first to appear. You may notice them just a few hours after the sun comes out. “Ants are usually one of the first pests people notice after heavy rains,” Druschun says. “Their colonies can quickly flood, and workers begin searching for dry ground, often inside homes.”
Small-scale ant infestations can be dealt with with simple DIY options such as commercial baits and sprays, but persistent problems may require professional pest control.
rodent
If you see them: Move and stay within hours
Heavy rains can cause flooding, and even small rains can push rodents from their hiding places into your home, especially into basements, crawl spaces, walls, and garages.
If a mouse comes in during the rain, don’t worry. This can be done with a mousetrap that can be purchased at your local hardware store. The real problem appears when rats and mice make your home their permanent home.
If the rodent problem persists, your best option is to contact a pest control company to exterminate the rodents and prevent them from returning.
mosquito
If you see them: A few weeks after the rain
Mosquitoes are a threat that appears late rather than immediately after the rain.
“Mosquitoes are different. They may not come indoors right away, but when it rains, they leave standing water behind. Mosquitoes will lay as many eggs as they can where there is standing water, so it can become a mosquito problem within a week or two,” Dorschun says.
To get rid of mosquitoes, remove standing water from all outdoor locations, including buckets and wading pools. Even with these efforts, it may not be possible to eradicate the swarm. “Anything that has water in it is more likely to have a mosquito problem,” says Dorschun. “Remove wet trash, leaves, and debris quickly and seal food indoors.”
You can also install mosquito screens around your garden to keep mosquitoes away. However, you may need a professional pest control company to completely eliminate the pests.
flies
If you see them: A few days after it rained
“Wet trash, debris, and organic matter left behind can also lead to a surge in fly populations after a storm,” Dorschun says. Like mosquitoes, these pests do not appear immediately, but can appear in large numbers.
Heavy rain can flood open trash cans and soak outdoor trash until it rots. Flies are attracted to things that have deteriorated, so cleaning the garden and closing trash cans can be very effective. If you have a fly infestation in your home, there are many DIY options available at affordable prices.
Why do pests appear indoors when it rains?
Rain brings pests indoors for two main reasons: movement and opportunity.
Heavy rain can cause flooding, and even small floods can destroy outdoor habitats such as anthills and rodent burrows. When water enters, these pests move out to find a new home.
Conversely, rain creates ideal conditions for certain pests to breed, such as mosquitoes. Damp foundations, clogged gutters, wet mulch, and standing water act as beacons and welcome unwanted pests into your home.
How to prevent pests before and after a storm
Prevention is the best defense against rainy day pests. “The best time to act is before the storm,” Druschun says. “Check for gaps around doors, windows, utility lines, and foundations, as these are the same openings that pests use to force them out of their outdoor hiding spots.”
- Seals entry points to prevent pests such as rats from entering.
- Eliminate standing water to prevent mosquitoes from breeding
- Clean up debris quickly before pests get in.
- Store food properly to avoid attracting flies and ants inside.
- Monitor early activity so you can catch pests before they become a big problem
Homes most at risk after rainy weather
Moisture is the main culprit, and older homes with poor drainage are especially vulnerable. “Water pooling near the foundation will attract pests to areas of your home that have the most entry points,” Druschun says. “The more water you have around your home, the more pests you have to deal with.”
The following factors can make your home very hospitable to pests:
- Poor drainage near the foundation
- old house
- damp crawl space
- clogged drain
- contact between wood and soil
- Landscaping risks (e.g. wet mulch)
- firewood stored near the house
- damp siding
How long does pest activity continue after it rains?
The extent and length of pest activity varies by pest, but can last from a few hours to a few weeks, especially if the rain comes on and off for days or weeks.
However, just because the rain has stopped doesn’t mean that pest damage will stop. The rain itself is the catalyst. Despite dry weather, subsequent pest activity may continue. “Rain is the beginning of the problem, but activity usually continues until the situation improves,” Dorschun said. “Waiting it out is not a great strategy.”
Unexpected pests that appear after heavy rain
Intruders aren’t just the usual suspects. Other pests (some even more destructive) can also make unwanted appearances.
“Millipedes are one of the most common invaders after rain,” says Dorschun. “They live in moist soil and leaf litter, and when those areas become saturated, they can migrate indoors in large numbers.” Collembola (flea-like insects), earwigs, and even worse, termites may also appear.
“Termites are the thing that homeowners should take most seriously,” Druschun says. “Heavy rain can spur termite activity and cause termite swarms. If you see winged termites or discarded wings near windows or doors after rainy weather, they shouldn’t be ignored.”
If you notice any signs of termites, call a termite exterminator immediately.
When to take pest activity seriously
Try some DIY pest control methods first. But if that doesn’t work, or if you see signs of a more serious pest infestation, contact a professional. Contact your local pest control company if any of the following apply to you:
- repeatedly seen indoors
- Structural risks (termites, rodents)
- Persistent moisture problem
