Carpenter ants stay in soft or old wood and make tunnels in it. The one ant might have entered the house by itself or there might be more ants in a wall or in the edges of a door or window. They make nests in tree stumps outside and in something made from wood.
I went in my bathroom upstairs and found a pretty big black ant my dad said he's gonna spray later he said their carpenter ants will spray get rid of em
