Carpenter ants got their name because in the colonial era houses were made with green lumber (fresh cut, very high moisture content. The ants would move into these pieces of wet wood before the carpenters were even done constructing.
Medium sized carpenter ants (bigger than sugar ants but not as big as worker carpenter ants) in ones or twos are not generally an issue. Those are the rangers (also called pharaohs). Their job is to look for nesting opportunities.
To have a problem in your house you need to have a situation where water is getting on wood. A leak, splashing against a sill, etc. The ants need water for a colony. Not a huge amount, but if the supply is too intermittent the colony will die. If they have the conditions right, workers will move in and start to tunnel through the wood. They are capable of incredible amounts of damage. Unlike termites, they do not eat the wood, so one of the first indications can be finding little balls of masticated wood.
The best way of checking for an infestation is to go around your house with a stethoscope and listen to the walls and ceilings. If there is a colony you will hear them chewing.
I have had good luck with the baits designed for exterior placement. I have also physically removed whole nests from people’s houses, fixed the leak and they never had a problem again. FWIW I have been bitten by the ants many times while doing that.