Thanks, Val for clearing that up for me and informing the others. What the lady gave me was a rectangular bar shaped white chalk.

Yesterday I see stopped for some food and I could see the white lines scribbled all over the legs of the vendor's food preparation table. No ants in my food, that I could see. It must work.

Mainer wrote:Does the word "blackboard" date me? I dont think they have used BLACKboard in many decades.

Walk into any government school and you will blackboards. Virtually all of them are in terrible condition and difficult for any student to see what is written on them - much less even more difficult to write on. Another reason for the failure of the Thai education system... But, that is another rant...

I've noticed they don't like and won't cross ordinary white powder, like chalk or talcum powders, but as Val says there is a special pesticide in chalk form (a stick) which they won't cross and which kills them. I usually track down where they are coming from and where they are going to and then encircle each end of the trail.

I say "chalk it up to experience"!!

A previous GF used to stand the table legs in a small dish stood in a larger one part filled with water, so they couldn't come up the legs of the table!

A follow-up on Banpaeng's post last year about Stedfast 4 SC bug spray from Homemart. We started having ant problems too and tried the canned sprays around the doors and windows without much effect. And I didn't want to use too much in the kitchen. Found this thread and tried the Stedfast but I was a little afraid to use it in the house so I sprayed around the base of the doors and outside walls. That helped a lot but the rain came and some of the ants came back and they never did completely leave the kitchen. So I looked on the net and found out the stuff is pretty well known and is actually listed for use in food storage areas and as an inside wall spray for mosquitoes. It's even used to soak bedroom mosquito nets in so I figured it was reasonably safe. I picked up one of those 8 liter wand sprayers and mixed up a batch. We cleared out the kitchen cabinets, covered the pots and pans and counter tops and sprayed inside the cabinets and around the base and tops of the walls in the kitchen. Outside I sprayed a circle around the doors and windows and a band around the walls of the house about 6 or 7 feet up so the rain wouldn't wash it off. For good measure I sprayed the garden and garden wall as well. About 4 liters all together.

That did the trick. The ants decreased immediately and even the stragglers were gone after 3 or 4 days. It's been a couple of weeks and they haven't been back. It's listed as suppose to work for 9 months but should be re-applied after 6. We'll see. A bit of work at first but a lot better than having to continually put out ant baits or powders, etc.