I found a carpenter ant nest from following ants and they all came back in this 1 little crack in the wood. I blocked it off with a card so they cant get in or out. This was a few hours ago. Now several ants are trying to get back in. I have no idea what I should do. Let them be? kill them? spray? poison? take the card out?

Please dont say call a professional because if i need to i will but i mean for right now at this moment what should i do