So been dealing with an ant problem and finally found a solution. The main problem was the ants just wouldnt find or go to the the poison traps. So it wasnt effective. But I found a way to fix that.
Leave some food out so you have a line of marching ants going to and from it. Most likely this already happened if you realize you have an ant problem at all.
Go to the end of the ant trail that is close to the food but where the trail is still a tight line (as it gets close to the food they will spread out to cover the food). Take a drop of cooking oil about 2/3ths the width of the poison container and put it directly on the ants making the trail. Then take a paper towel and wipe a very wide streak (a good meter should do it) in both directions from the blob. This will create a tin coat of oil the ants can not walk over (it will get on their feet and then they cant stick to stuff so they avoid it)..
At this point the ants will try to find a way around the barrier and will start trying to look for a way around the oil. Take your poison trap and place it exactly where you put the oil, right in the middle of the line of ants. make sure the streak of oil is thin enough that the trap creates a complete bridge (if any oil pokes out from under the trap it wont work).
the ants will quickly find the shortest new path which goes through the trap and across the poison. Once the ants have established a path through the trap to get to the food clean up all the food and leave the trap.
Now the ants will start taking the poison back to their nest instead of the food.
@Rado1 That woukd be borax then.
@freemo what I'm using is not just simple poison. It is something that will destroy the whole colony when the ants bring it home as food.