Make sure and do your reading first, dry ice can be dangerous. There are already a lot of older threads on the subject so I won't repeat myself.
Basics...its REALLY cold...losing fingers cold...C02 is heavier than normal air...100% sealed container + dry ice = bomb...
I am totally sold on the Terro liquid drops..best thing for ants I have ever found.
they are quickly drawn to it and large numbers of ants suck up the liquid and take it back to the colony..
sometimes so many ants that I have to replenish the "puddle" once an hour or so! they drink it dry.
we have had ants in our kitchen..One day of using the terro liquid, and ants are never seen again.
They might have been carpenter ants..cant risk that.
so we had to get rid of them.
if they had just been out in the yard, then no problem, I would leave them alone..
but large ants living in, and possibly chewing on the timbers of your house..we cant co-exist with that.