Frank,
What type of ants are they? Are they the black type carpenter ants?
Those little buggers must be nesting some where in the house if they're coming from the middle of the house. You need to find their point of origin and work from there to tank'em once and for all. I'm really surprised that you're seeing them now especially with everything frozen ie. ground, tree trunks etc. Something must've changed temp wise now that you're seeing them.
I had my episode with them last spring with hundreds getting into the house. They were coming through the front of the house through a small gap in the front door. I was able to determine the worker trail and worked back to a dead tree trunk in my neighbors yard about 100 feet away. Carpet bombed that part of the yard and it put a stop to it. We'll see what happens this spring. Hopefully it won't be a repeat but we'll see. I'm armed and dangerous.
well,
It is that time of the year again. Every year about this time we are invaded by little pissants. My Daughter just spotted some in the livingroom. The weird thing is it is in the middle of the house away from outside walls.
I made them up a batch of apple jam and borax. Now they will have a big party and die.
They usually show up after a real cold snap. they make my shin crawl.