They might have been there last summer. You don’t normally see them at first.
I’ve lived in two (rental) houses with massive termite infestations. One they literally swarmed the living room and we had to get a hotel room because you don’t want to live in a giant bug swarm.
One we had termites so bad that the house had woodpeckers. That was hilarious.
So like, houses can withstand wood eating bugs for a while and be fine.