One of the great secrets of organic gardeners to kill ants without using poisons is to use something as simple as an orange that is "rotten".
That dust that develops on the peel of greenish-white or blue-gray citrus fruits is a fungus called Penicillium.
The Penicillium will engulf the fungus that the ants produce in the anthill to feed. Without food, the ants will have to leave the anthill to avoid starvation and will go elsewhere.
How to eliminate ants with orange
The procedure is simple, you have to identify the anthill following the path of the ants or get as close to it as possible. Once the main hole is discovered, the oranges or any other citrus fruit contaminated with Penicillium is washed. The washing water is what will be used to pour it through the hole of the anthill and spray the entrance.
If the anthill is not found, it can be carefully removed, for example by scraping with a knife, the Penicillium dust. The powder is mixed with grains of rice, the most economical, and is placed in small heaps in the path of the ants, taking care that it does not get wet with dew, irrigation or rain. The ants will take away the “contaminated” rice that will have an effect on the anthill. In a few days, they will leave the place.
For this treatment you need patience and persistence since the result is not immediate, but it works, it is economical and ecological.