I have carpenter ants in my yard around my house. How can I prevent them from coming in the house? I don't want to have to use chemicals to get rid of them.
Carpenter ants want a ready food source and moist wood is their favorite comestible. They tend to stay outside, especially if your home is close to green space, a park or forest with downed wood, a pasture, etc. They will send out scouts to find new food supplies, so occasionally you may see one in the house. Unless you have issues with moisture such as a leaky roof, a refrigerator with a drippy ice maker, or a damp area in the kitchen, laundry, or bathroom, or even a damp crawl space under the house, the chances are good that you won't develop a carpenter ant problem. However, if you do have a problem (whether you see it or not), it's like hanging out a "Free Food" sign for them.
Two key ways to determine if you have a problem is to check around your home for fresh sawdust. It might be out in the open or in a less conspicuous place. The second is to stay up late a few nights between April and October from 10 pm to 2 am and check the perimeter of your house for ants. Look for a two way street with ants coming and going. Once you find them, track them to their nest. At that point you can hire an exterminator to get rid of them. If they are in the house, the exterminator can inject a pesticide in a powder form into air spaces where the nest is located. The poison is deadly to ants but inert to humans because it's dry and remains where it's placed.
Hire only qualified extermination services that have a contractor's license in good standing with your state contractor's board.