They are probably living in someones pot plants, or in some wood, or in a wall...
The future queens and the drones fly at breeding time, and the new queens then land and start a nest, so that can be anywhere an ant can fly or be blown to
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They are probably living in someones pot plants, or in some wood, or in a wall...
The future queens and the drones fly at breeding time, and the new queens then land and start a nest, so that can be anywhere an ant can fly or be blown to
I heard you do lemon zest, vinegar or chalk. Ants don't like that or strong odors. So last time they came into the house I didn't crush any of them, just placed a towel with some vinegar in their way for 2 days and that was it. Btw, they came out of a flower pot that I had moved too close to the door.
In the 4th floor I'd likely just use the vacuum cleaner on them and immediately empty it outside into the trashbin. And maybe check where they came from. Maybe there's food or a crack somewhere. Or your neighbour is deceased or has a marijuana farm next door.
I keep checking next door, hoping my neighbours are deceased and left me some weed, but no luck so far.
I can verify the chalk from personal experience
TIL ants like to get baked
I have seen ants form nests in decomposing organic litter on roofs higher up than you are.
Some species of ants may travel 100m to forage, but that is rather exceptional a distance for most varieties.
My guess is some foundation ants or similar have a nice easy shot into the building and the scouts discovered your place.
It would be prudent to report it to the management, so long as you do not expect some negative outcome for you. Otherwise just keep your place clean and kill them as you see them and they should only be a problem once or twice a year.
Stairs?