October 16, 2002 | By: Laura Skillman

As temperatures cool, spiders, flies and lady beetles may begin invading homes around Kentucky. Pest proofing, or cutting down on entryways can reduce problems indoors.

Some of the same techniques used to keep pests from inside a home can also help conserve energy by keeping heat inside. Mike Potter, University of Kentucky Cooperative Extension Service Entomologist, offers six steps to help keep pests out. Install door sweeps or thresholds at the base of all exterior entry doors.

To see if you need sweeps, check for light filtering under doors while lying on the floor. Gaps of a 16thof an inch or less will permit entry of insects and spiders while a quarter inch wide gap (the diameter of a pencil) is a large enough for entry of mice. Pay particular attention to the bottom corners, as this is where insects and rodents often enter, he said. Apply caulk along the bottom outside edge and sides of door thresholds to exclude ants and other small insects.

Garage doors should be fitted with a bottom seal constructed of rubber because vinyl weather stripping may seal poorly in cold weather. Gaps under sliding glass doors can be sealed by lining the bottom track with a quarter inch to 3/4 inch-wide foam weather strip.

Additionally, seal utility openings where pipes and wires enter the foundation and siding, such as around outdoor faucets, receptacles, gas meters, clothes dryer vents, and telephone/cable TV wires. These are common entry points for rodents, ants, spiders, yellowjackets and other pests, Potter said. Holes can be plugged with caulk, cement, urethane, expandable foam, steel wool, wire mesh, or other suitable sealants.

Caulk cracks around windows, doors, fascia boards and other areas where it may be needed. Use a good quality silicone or acrylic latex caulk. Although somewhat less flexible than pure silicone, latex-type caulks clean up easily with water and are paintable. Caulks that dry clear are often easier to use than pigmented caulks since they don't show mistakes.

Buy a good caulking gun. Features to look for include a back-off trigger to halt the flow of caulk when desired, a built-in "slicer" for cutting the tip off of new caulking tubes, and a nail for puncturing the inner seal. Hardware stores sell guns with these features for less than $10. Prior to sealing, cracks should be cleaned and any peeling caulk removed to aid adhesion. For a professional look, smooth the bead of caulk with a damp rag or a moistened finger.

Repair gaps and tears in window and door screens. Doing so will help reduce entry of flies, gnats, mosquitoes and midges during summer, and cluster flies, lady beetles, and other overwintering pests in autumn. Certain insects, in particular leafhoppers and hackberry psyllids, are small enough to fit through standard mesh window screen. The only way to deny entry of these tiny insects is to keep windows closed during periods of adult emergence.Install quarter-inch wire mesh (hardware cloth) over attic, roof, and crawl space vents to prevent entry of birds, bats, squirrels, rodents, and other wildlife.

Be sure to wear gloves when cutting and installing hardware cloth, as the wire edges are razor sharp. Invest in a chimney cap to exclude birds, squirrels, raccoons and other nuisance wildlife.

Finally, consider applying an exterior (barrier) insecticide treatment. While sealing is a more permanent way to exclude pests originating from outdoors, comprehensive pest proofing is labor-intensive and sometimes impractical.

For someone requiring an alternative, pest proofing can be supplemented by an exterior treatment with an insecticide. Homeowners will get the most for their efforts by applying longer-lasting liquid formulations containing synthetic pyrethroids sold at hardware/lawn and garden shops. Apply with a pump up sprayer, hose end sprayer or other applicator, treating at the base of all exterior doors, garage and crawl space entrances, around foundation vents and utility openings, and up underneath siding. It may also be useful to treat around the outside perimeter of the foundation in a 2 to 6-foot-wide band along the ground, and 2-3 feet up the foundation walls.

Anyone who chooses not to tackle these activities may wish to hire a professional pest control firm. Many firms now offer pest proofing as an adjunct to other services.When all else fails, a vacuum cleaner or broom is often the best response to the occasional bug that wanders in from outdoors.


Mike Potter, 859-257-2398