Ant in Upstate NY
The image is too out of focus to ID but the general shape seems to indicate a beetle, not an ant.
The weather this year has been wet and many organisms have remained near the soil surface. They seek shelter from the cold and the heat by heading for shaded areas which some times is the space at the base of your door and spaces at windows. Once inside, they have trouble finding their way out or decide to stay because they found food and shelter inside. In either case you will need to catch them and show them out.
Thanks so much, Ed - you're right that it's a beetle. I can tell because 1 just (surprisingly) jumped up.