Chinese Ant Chalk

First used this stuff in Japan. Bought some in Thailand a year ago and are using it now inside because a tiny ant colony has been marching into our kitchen area and finding every crumb and unwiped spot that had something they like. I have enjoyed watching them crawl out of the stove fan vent in the ceiling and walk upside down to the column above the dining table.
Time came to thwart their efforts so I circumscribed a line of chalk around the vent and that stopped them. Hope the ones who couldn't return found another route. I bet so as their sisters have found other routes in though we marked them off too. Haven't seen any in a few days. There were more persistent ants on the balcony of our hotel room in Bangkok and I drew a circle around where I sat there and noticed that some got through - they were bigger. Not that big a deal cause they weren't biting ants which seem to be only the bigger red ones. Here's Wikpedia on this most noble stuff.