I am in a constant battle with ants in my kitchen, they are tenacious little buggers and the only way that really works is to keep the kitchen immaculately clean!
Leave this Mixture in a shallow lid/dish next to the Ant entry point:
1 part borax dish soap
3 parts granulated sugar
15 parts warm water
They will ingest the mixture, and return the payload to the colony if dilute enough. A few days later the slow poison should start to knock out the group.
Indeed, once a path is chemically marked it is very hard to keep ants out, and failure to remove a waste bin lures them in again.
Mixing kiln dried diatomaceous earth with water for treating the surrounding external structure also helps knock down anything with a chitin exoskeleton. It can be effective if a colony has attached to a tunnel system.
Best of luck =)
1. Give them what they want. I have a bottle of cheap corn syrup I use as a truce offering. If I start getting scouts or the beginnings of an incursion I just dump a big glob of the syrup right next to their nest outside. Everyone disappears from my house within a half hour. Usually, they forget about the kitchen for a couple weeks. Then I repeat.
2. Peppermint oil. The ants here will avoid it. If I smear it across an active ant line it interrupts it even.
3. Ant moat. Works great for sugar products and pet dishes. I use 4 shot glasses full of soapy water holding up a small kitchen rack. The rack is perched on 4 small submerged pillars I added to the rack's feet.
Edit: of course an invasive species needs to be dealt with in accordance to the threat to the local ecosystem. I'm just providing options for simple nuisance ants.
Not a great idea, as people can skew the ecosystem into causing more harm. More ants can increase Aphid populations that spread viral plant diseases (see Huanglongbing or citrus greening disease).
"2. Peppermint oil."
Never tried this one, but seems expensive. Also, most mint products are illegal to import in some areas, given it can carry symbiotic fungus spores that may decimate food crops.
"3. Ant moat. "
Many species have building skills, and some will even build tiny twig/gravel roads/bridges over dangerous/irritating substances.
They are fascinating little creatures, and an important part of the ecosystem. =)
Nonsense. A wipe with plain white vinegar suffices to dissolve the pheromone trail, and seems to deter foragers for some while after.
As for the rest, I certainly don't imagine it working all the time everywhere, but for the local pavement ant colony's roughly annual sortie into my kitchen it's fine. And what do you find of idealism in my not wanting to poison the room I feed myself in?
They get into toilet tank, cat's water bowl, flower vase, my cup, looking for nothing but water. Not once had I seen them moving any sort of food in my house, (they also doesn't seem to be interested in cat food), but they always manage to find water. I wonder how they manage such a low calorie diet.
It took quite a bit of effort to caulk every one of their entrance; which seems to be the most effective measure so far.
Prevention better than cure, as always :-).