If you see ants in the house, it’s important to address them quickly, because they can spread throughout your home and pose a health hazard. Fortunately, there are many ways to kill ants and keep them away. You can use ant baits, sprays or perimeter products. The key to success is proper placement of the product and checking for the ant trail and entry points regularly. For indoor treatment, ant baits work best because they’re safe to use around pets and children. Liquid products such as ant killers should be sprayed on the outside of your home and any external structures, like sheds or barns, to prevent ants from traveling through them to get inside the house.

A typical ant killer, such as a commercial product from Terro maurspray or another brand, is a mix of ingredients that attracts the ants and then poisons them when they ingest it. The ant will bring the poison back to the colony and share it with the rest of the workers, thereby killing the entire population.

Borax, also known as sodium tetraborate decahydrate, is the primary ingredient in most ant baits such as TERRO. It’s a naturally occurring mineral powder that has been used by consumers for more than 150 years. Stewart Clark, director of research for the ant bait company Terro, explains that the borax kills ants by interfering with their digestive and metabolic processes. This causes them to lose water and nutrients, resulting in starvation and death.

Another commonly used ant killer is diatomaceous earth, or DE, which works by lacerating and dehydrating an ant’s hard exoskeleton. It can be found in most garden centers and is usually labeled as “food grade.” It is important to use only food-grade DE, as it is also very dangerous if inhaled, so use it only outdoors or in well-ventilated areas such as crawl spaces.

You can also create an ant barrier by spreading granule baits, such as the popular Advion WDG, around the exterior of your home or other buildings. This can be effective in keeping ants from entering the structure, but it’s a less-efficient way to kill them than using low-impact perimeter products, which are more targeted and easy to apply to specific ant trails and entry points.

A natural method of repelling ants is to use neem oil, a liquid that can be purchased at most health food stores or online. Its strong odor disrupts ants’ pheromone trails, making it difficult for them to find their way in and around your home.