This is a good, general article, applicable for the types of ants we experience in the Portland Oregon area.   It doesn’t go into any depth in terms of the strategical processes a professional pest control technician would use for best results, but is is helpful for a obtaining base  understanding of problem. – Tom

On any given day, you may see hordes of ants, marching into your home. They may be searching for food and water, shelter from outside elements.

Here are some steps you can take to get rid of these industrious creatures.

1. Follow the ant to its source of entry, could be a window, molding crevice or floor crack.
2. With Boric acid, form a barrier at the source, or use laundry detergent, must be in powder form.
3. If they have attacked any food, remove it to a garbage container, outside your home.
4. If they have invaded your kitchen garbage can, take it outside, hose it out and wash with dishwashing liquid.
5. Put any food they have NOT found in zip lock bags, or in sealable plastic containers. or the refrigerator.
6. Ants can penetrate metal-threaded lids on glass jars. Glass jars are immune from ants, only if sealed with rubber gasket.
7. Once you have secured the food,vacuum up the ant line, along with some cornstarch( this helps to suffocate them inside the bag).
8. Use dishwashing liquid and hot water to wash the area around the ant line to erase any scent of the trail.
9. Seal the area where the ants entered; caulk windows and cracks and weather strip doors. Apply duct tape or petroleum jelly over holes as a temporary fix.
10. Go outside and see if you can find out where the ants entered the house. They may have used an overhanging branch to enter, if so, trim it off.
11. Check the area in an hour. If you see any single ants, or scouts searching the area, squash them( sorry!) but they are checking out the area for future invasions!
12. If you wish to wipe out the ant population, use ant traps that contain" Boric Acid". The returning ants poison the whole colony.

I would point out however, that in the garden, ants can play a beneficial role, so only use the above method if absolutely necessary
Here are some tips that may help;

Some natural ant deterrents include crumbled bay leaves, cinnamon, peppermint leaves and cayenne pepper. If an indoor plant is infested with ants, take it outside and flood it several times with a hose, to remove them.Insecticidal sprays kill only the ants that you spray, which will be a very small percentage of a colony, and won’t prevent future invasions. Please make sure, if you do use a spray, keep children and pets away.

In the house, I found that sprinkling the doorways with a powder cleaner ie, Ajax, kept the ants from crossing the line of powder and they did not enter the house.

One word of warning!! If you have Carpenter ants, which are a larger species, as they burrow into wood and cause terrible damage, do NOT keep any piles of decaying wood near your house, as this attracts them.

The methods I have outlined above, if used diligently, should go a long way to eliminate your pesky visitors.

But that doesn’t mean that there is no pest activity during winter.   Particularly during untypically severe weather, some pests can be prompted into action.

As mentioned in the previous post, rodents are one of the most common critters to start showing up during the cold months.   Hey, they prefer the warmth just like us.   These months are a good time to check and repair obvious entry points such as loose exterior doors, damaged screens, and exterior insulation around pipes and venting.    Be sure to keep food tightly stored and avoid excessive clutter (I know that is hard to do right after Christmas and the holidays!)

By no means do rats and mice have the house to themselves, however.   Roaches can often show up during this time of year.   While they are much more common in restaurants (sorry for mentioning this – I don’t like considering this fact either) and higher traffic residences such as apartments or motels, they still show up in single family homes.   Being the prolific breeders that they are, finding even one is cause for taking prompt action.   Always give a good inspection to any used furniture, packages stored remotely for extended periods of time or large boxes for potential intruders.

Another group of pests not shy to show up in winter are "pantry pests", meal moths and other related species.   Like a roach, they can travel into your home via outside sources.   Keep an eye on dry goods such as flour and cereals, birdseed and other carbohydrate heavy food stuffs.   Also take quick action if you spot any webbing or larvae where you keep your food.

Finally, it is not unheard of to see ants, both Carpenter Ants and small ants (usually odorous house ants) during this season.   It will usually be the wetter parts of the home (kitchen sinks, bathrooms, and laundry rooms) where you will first notice them.

The cold temperatures are pushing some of last mice and rats indoors for more comfortable nesting.   This migration commonly happens throughout the fall, but recent cold is forcing the issue with those that had yet to seek warmer surroundings.   Often, after strong fall rains and winds, a few more entry points to structures have loosened and opened up.   It doesn’t take much space for a mouse or rate to squeeze through a gap.

This is an especially important time to keep floors and hidden areas clean of loose food.   Every rodent that survives through the winter is primed to start breading soon thereafter.   With their short gestation periods, quickness to maturity, and large litters, things can get quickly out of hand come spring.   So if you see any signs of intrusion, it is wise to take quick action right now and save yourself alot of money and headache in a few months.