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Indoor insect numbers up with weather change
MISSISSIPPI STATE -- Insects and humans seem to like similar weather, so when damp and cold winters set in, people often find they are sharing their house with unwanted guests.
James Jarratt, entomologist with Mississippi State University's Extension Service, said most insects are simply opportunistic, seeking protected places to live.
"Cold usually doesn't kill insects, they just move inside looking for a comfortable place to stay," Jarratt said. "Most insects just wander in houses and stay when they find them warm and dry."
Key to keeping out insects is sealing up holes and crevices where they can enter. Houses today are built tightly, but insects and even mice can crawl into very small spaces and get inside. Jarratt advocated caulk as one of the best ways to keep pests outside the house.
"Use good quality caulk around doors and windows, especially on shifting soil," Jarratt said. "Caulk around any service lines that go through a wall to enter the house, but be very careful around electrical wiring."
Brick homes have areas of particular concern when keeping out insects. A facia board at the eaves where the brick wall meets the rafters generally covers the top row of bricks. It is hard to seal this area effectively, but apply caulk carefully where the brick wall meets the board.
Brick houses also have weep holes left open to allow the walls to breathe. These are typically a row of mortar left out between two bricks near ground level that allows air to pass. Since these weep holes provide access to the house walls, spray insecticide in these holes in the fall to keep insects away.
Another problem area is vegetation growing close to the house that provides easy access to walls and hiding places for insects.
"Give yourself some working space between your ornamentals and the foundation of your house," Jarratt said. "Don't let your plants grow up tight against the house. This will keep insects from moving into the house and it gives the homeowner some room to work."
While most insects are simply opportunistic, Jarratt said wasps are a particular concern in the fall as they actively seek out a winter home. Spray the house's eaves in the fall with an insecticide for wasps, and be sure open areas are sealed with caulk.
Fall is an ideal time to prep the house to keep bugs and mice out in the winter.
"Hot and dry weather causes insects to move inside the house just as cold and damp weather does. When the weather is good outside, insects don't try as hard to move in," Jarratt said. "Once weather moderates in the spring, they move back out."