Try pouring a line of cream of tartar, red chili powder, paprika, or dried peppermint at the place where you think ants might be entering the house; they won't cross it.
Cayenne pepper / Black pepper
How it works: The spicy, strong scent of cayenne pepper (or black pepper, if that's what you have) irritates ants, and they try to avoid it. Pepper's scent also masks the ants' pheromone trails that lead them to food sources in your yard and home.
Cinnamon is a great option for killing ants. When an ant inhales cinnamon, it suffocates and dies. You can use ground cinnamon and sprinkle on the ants' path or around an anthill opening. Cinnamon essential oil also works well to repel ants.
Spray Tea Tree Oil
Like peppermint essential oil, ants can't stand the smell of tea tree oil and try to avoid it at all costs. Use the same peppermint oil spray bottle method or soak cotton balls in tea tree oil and place them at every entry point.
Use this white vinegar solution to spray all entry points of your home, try to spry all windows, doors, baseboards and the common paths that ants would travel within your home. Give about an hour for this solution to take effect, then after a few hours the ants should be dead.
Utilize naturally deterring scents
The scent of peppermint oil, lemon, and cinnamon will deter ants. Try spraying diluted oils around your kitchen, or sprinkle cinnamon where you've seen ants congregate. "The domestic spice acts as a dermal irritant, which will keep them away," Warberg Block adds.
Diatomaceous earth (DE) is not only inexpensive and effective; it's non-toxic to kids, birds, and pets. And yet it destroys ants, earwigs, slugs, beetles, ticks, fleas, cockroaches, and bed bugs. As these pests move across the powder, it sticks to their feet and legs only to get into their joints and exoskeleton.
You may love your morning coffee, but ants could do without it. Another natural way to deter ants, sprinkle coffee grounds outside and around your garden. The smell repels them and they'll be looking for a less caffeinated place to hang out.
A simple eucalyptus oil solution or a concentrated garlic spray have both been known to put ants off and the best part it is this won't harm your harm your plants, or you!
While many people believe that salt is an effective way to get rid of ants, the truth is that salt may only temporarily repel certain species ants, rather than kill them. Ants live in a colony often consisting of thousands of ants.
If you know where ants are getting in, you can line these entryways with things that ants hate. Salt, baby powder, lemon juice, chalk, vinegar, bay leaves, cinnamon, or peppermint oil are a few items that you have around your home that will stop ants from coming inside.
Ants are very sensitive to pheromones, a chemical substance they produce and release into the environment. When a pheromone trail is disrupted by chalk or a line drawn in their path, the scent trail they were following is temporarily disrupted.
You can eliminate the pheromone scent that forms ant trails by spraying a mixture of water and vinegar onto it. Mix equal parts white vinegar and water in a spray bottle, spray down the ant trail and wipe up with a paper towel. The scent of vinegar also acts as an ant deterrent, but will only last for four to 48 hours.
Straight white vinegar makes a great ant spray. You can saturate ant trails to kill on contact, or spray counters and other areas and either wipe up after a few minutes or allow the treatment to dry in place.
Always remember that Vinegar is not a permanent solution to remove an ant infestation. It is reasonable to spread the solution thrice a week over the affected areas to remove ants slowly.
Unfortunately, it doesn't work. Vinegar does not kill ants in the traditional sense: you spray it, and the ant dies. The only way this remedy is effective is if the ant drowns in vinegar (though water accomplishes the same thing).
Mix one part powdered sugar with one part baking powder, and leave the mixture in corners of your kitchen where ants are located. The ants will be drawn to the sweetness of the sugar, but it's the baking soda that will kill them when ingested.
Baking soda; vinegar; lemon juice; some detergents (and cleaning products); Tabasco sauce (and other spicy substances, such as red chili pepper, black pepper and cayenne pepper) usually repel ants to varying degrees, and you may have seen them trapped in these circles.
A white vinegar and water solution is a common method to wipe out ants for good. Ants don't like the smell of vinegar. It not only repels them; it can also kill them. Depending on how much you can bear the smell, mix at least one part vinegar and three parts water.