Remember those stink bugs that drove you crazy last winter?

Nowís the time to act if you donít want a repeat appearance.

Fall is when brown marmorated stink bugs make their way into buildings in search of a warm place to spend the winter. Once theyíre in, itís too late to do much about them, so your best defense is to prevent their entry.

That involves buttoning up the house as best you can. For homes that have experienced big invasions, it might also mean calling a pest-control expert for guidance and possibly one or more exterior insecticide treatments.

Where should you start?

The attic, recommends Dave Shetlar, an entomologist with the Ohio State University Extension.

Insect experts like Shetlar have known for some time that stink bugs get into our homes through little cracks and openings, and theyíre realizing that attics are major ports of entry for the pesky creatures. Nylon mesh soffit vents and filter material on ridge vents can deteriorate without homeowners realizing it, he said, and that can leave openings for the bugs to enter in droves.

If stink bugs are a significant aggravation in your house, he recommends installing aluminum soffit vents and copper or stainless steel mesh under the ridge vents. Itís not a cheap or easy undertaking, but ďthe way I look at it is itís a permanent fix,Ē Shetlar said.

Itís also wise to seal any other openings in your homeís exterior that you can, said Shetlar and Jim Fredericks, an entomologist with the National Pest Management Association.

Repair door seals and weather stripping, if necessary. Fix or replace damaged window and vent screens, and remove window-mounted air conditioners. Use caulk or foam sealant to fill gaps around windows, spaces where pipes or wires enter the house and any other openings you can find.

Even stuffing cotton into the crevices of leaky windows can help, Shetlar said.

Fredericks recommended paying close attention to any place on your homeís exterior where a vertical surface meets a horizontal one. Stink bugs congregate on outside walls ó particularly on the south side ó to warm themselves in the sunís rays, and then they crawl upward till they reach a horizontal surface such as a soffit or roof overhang. Thatís often where theyíll find a spot to get in, he said.

A qualified pest management pro can help you pinpoint problem areas, Fredericks said.

He and Shetlar agreed that blocking the bugs by physical means is the best approach, but Fredericks noted itís not always possible to seal every opening.

ďItís always better to seal a crack than to treat a crack,Ē he said, but insecticides can be used as a supplement in some cases.

Products that are registered for indoor use arenít effective against stink bugs, so the only insecticide option is one or more exterior treatments in fall to keep the insects from entering, Shetlar said.

The most effective insecticides last only a few weeks at best, he said, so keeping the bugs out might require repeated treatments and the expense that involves.

If thereís an up side, itís that stink bugs donít bite or sting, nor do they cause structural damage or breed indoors. Theyíre not known to transmit diseases directly, Shetlar said, although when large numbers of the insects die indoors, their decaying bodies could cause problems for people with conditions such as nasal allergies or asthma.

Better to keep them out in the first place, he said.

Mary Beth Breckenridge can be reached at 330-996-3756 or mbrecken@thebeaconjournal.com. You can also become a fan on Facebook at www.facebook.com/MBBreckABJ, follow her on Twitter @MBBreckABJ and read her blog at www.ohio.com/blogs/mary-beth.