Boric acid is effective in killing ants and cockroaches. It is generally considered an organic pesticide. It won't sicken people or animals.
I believe the chaulk you speak of has more than boric acid in in, some pretty bad chemicals, as you can not buy this product in the US.
There is a product locally available called "Terro Ant Killer", it is boric acid based. It's a gel that you place in the ants path, they take the bait back to the nest and the nest dies. I was given a bottle to get rid of the sugar ants at Island Perk (we use sugar based syrups for the drinks)and in a weeks time, no more ants. We haven't had a problem in almost a year now. I last saw some bottles at Harmouch for about $10 BZ. I can't recommend this product enough.