50 minutes ago, timendres said:

As I mentioned, the key is that whatever you are using has boric acid, or some other chemical with similar properties. The boric acid typically kills the ant later, hopefully once it is back in the nest. The other ants deal with the dead ant, and are likewise killed. The process repeats until the nest is history. This is the only true solution. It appears the Quantum product mentioned also has this exact quality (maybe it is simply boric acid in a delicious gel).

Sorry I reference the chalk as your boric acid.  Your acid can never get rid of ants completely it just moves them to other location basically containing them until you drop another crumb.  As for a gel personally I don't want acid powder or gel all over my apartment, house or condo it is just unsightly. Here in Thailand, I go to 7/11 get a 98 baht can of Chaindaite spray with a small metal straw spray it into the hole they come in and out of smells a bit but does the trick for me not powder or gel all over the place for people to see unless you don't have visitors?

Most sprays just kill the ants you see, in a week they are back. Borax/boric acid is the best solution, but it takes time (about 2 weeks). I did this about 5 years ago and it took 2 years for the ant population to recover. Unfortunately it is very difficult to buy borax in Thailand, i have failed to get any. I bought my lot of Borax from the UK, but i felt very uncomfortable going through customs with a half kilo of white powder in an unlabeled plastic bag! Unfortunately all gone now.

 

Bayer quantum seems extortionately expensive. ARS is cheaper.

 

Being surrounded by a large garden, keeping ants out completely is a losing proposition, and I am not going to spray poisons everywhere (people here seem paranoid about pesticides in their food, but happy to spray there living quarters frequently). I use borax (if i have it), washing up liquid as a spray (you need to use a fair bit, as it works by blocking their spiracles) or if a few get on my desk i use a squirt of Soffel natural mosquito repellent, that kills those it touches and sends the rest running.

 

In the garden, ignore the ants except for the little red fire ants - they get tracked to their nest and given a nice mug or 2 of boiling water .....

I filled my garden sprayer with a poison I got from a garden shop. Found some openings to a nest and pumped the poison into the ground. . Filled the sprayer up two times. I could see the liquid coming up in holes everywhere in a 20 ft radius. The next day there were millions of dead ants. Eggs had been brought to the surface. I did it again. All in all I probably pumped in five gallons of the poison mixture. Didn't see anymore outdoor ants for years.  Was lucky that I almost never had any indoor ants. But used Quantum and never left food out and kept the kitchen spotless. 

I used to find the ant chalk quite effective also. I did a few "experiments"with it " yeh they do eventually cross but the contact with the chalk seems to kill them as well afterwards. downside was having white chalk lines written around my room. it also loses its effectiveness after awhile. all this time I was thinking "Ant rid" (a very effective poison popular in Australia) would sort them out. I brought a bottle over from Australia and couldn't believe it that Thai ants showed no interest in it whatsoever. I am guessing because Aussie ants like sugar but Thai ants like something else (money? :). 

The ant pellets they sell in supers work on ants inside for me, They take the food back to the nest.

On 06/03/2018 at 12:35 PM, Justfine said:

The washing liquid alone might work or dettol.

Chiang Mai pest control

Ants are a constant problem in our house.

 

For an instant fix, a plant sprayer with a dilute solution of washing up liquid (only a few drops in half a litre) works wonders.

 

It messes with the surface tension of water and inhibits gas exchange in their spiracles, or something!

 

Longer term, borax and honey works very well and can keep them at bay for weeks/months.

 

I'm going to try Bayer Quantum, though. It sounds good.