To kill ants instantly, use an upturned milk bottle lid as a tiny bowl, and dollop in just enough honey to cover the bottom of the lid. Mix in an equal amount of borax to create a syrup and leave the lid within reach of the ants.
The honey will attract the ants, but the borax is poisonous and will kill them.
Another quick and easy hack is to mix three parts white sugar with one part borax and leave it out for the ants to eat, walk through and take back to the nest, Eventually, you’ll see a decrease in numbers as ants in and outside the nest are killed off.
However, keep in mind these methods should not be used where pets and children can access the borax combinations.
Another quick and easy pantry solution for ants is to mix one part white vinegar to one part water and apply the spray to the ants. It’ll kill them, but it will also work as a deterrent, so spray the solution around windows or doors where ants may be entering.