You're describing carpenter ants and I'm pretty sure the ones with wings are what we refer to as carpenter ant swarmers. These are special ants also known as reproductives which colonies send out every spring and fall to start new colonies. Since they will only emerge from established nests, it's reasonable to assume you had an active nest last year which is now releasing these ants to go and start new colonies somewhere else. Because the nest is on the home, some are finding their way inside instead of outside where they really want to be. Since carpenter ants can cause a lot of damage to wood, you'll need to treat the nest as described in our CARPENTER ANT CONTROL ARTICLE.

Since you're finding them close to the window, one would naturally think the nest is somewhere in the vicinity. In fact this is a common location for carpenter ant nests to exist. But to be sure you need to follow the directions we outline in our article on how to track ant trails and locate where they live. As you'll learn, most any carpenter ant problem will involve multiple nests and if you wish to get rid of them you'll need to get all satellite nests. Hopefully you'll be able to locate the nests and if you can, treating them with DRIONE will provide the quickest control. If you're not able to locate nests and are at a loss for where they are living but see active worker ants, a thorough TERMIDOR application could resolve the problem. If all else fails, call a service company to do the treatment. Carpenter ants can cause a lot of damage and any activity on or around a structure is a sure sign of a nest close by. Letting it survive for any length of time could result in costly damage and therefore a thorough treatment of the area should be done to insure this isn't the case.

Here are direct links to the information and products listed above:

Carpenter Ant Control Article:  http://www.carpenterants.com/carpenter-ant-control

Drione Dust:  http://www.bugspray.com/catalog/products/page91.html

Termidor:  http://www.bugspray.com/item/termidor_sc.html