How to Get Rid of Grease Ants | Practical and Effective Solutions!

Written by Thomas Matthews

Grease ants, also known as thief ants for their sneaky food-stealing habits, are notoriously persistent pests both indoors and outdoors. With a penchant for protein-packed and greasy delights like meats, cheeses, peanut butter, and oils, these tiny bandits easily adapt to various environments, setting up shop in ideal conditions.

How to get rid of grease ants? Pinpoint their entryways and foraging paths. Disrupt ant pheromone trails by applying a vinegar-water solution. Strategically place borax or boric acid-based ant baits near these trails, targeting the entire colony. You can also use insecticide sprays and dust. After eradication, monitor the treated area to avoid re-infestation.

Get ready to bid farewell to grease ants! In this section, we’ll arm you with a comprehensive guide to banishing these pesky intruders. We’ll explore the factors that attract grease ants and provide a detailed, step-by-step plan for evicting them from your domain. Let’s dive in!

Grease Ants | Information

Grease Ants

Grease ants, also known as thief ants, are native to the United States and have staked their claim in Eastern, Western, and Central regions. They’ve even ventured into Northern Mexico, Southern Canada, and states like California, Mississippi, Illinois, Texas, and North Dakota. These tiny trespassers are true survivalists, able to thrive in harsh conditions.

Despite their small size, grease ants are mighty in their ability to set up colonies in a variety of locations. Indoors, they’re crafty enough to find homes in cracks, holes, under sinks, or behind cabinets and cupboards. Outdoors, they’ll burrow under rocks, in soil, beneath wood shavings, or wherever they discover an inviting environment.

What Are Grease Ants?

Grease ants belong to the genera Solenopsis, and are named due to their fondness for greasy food. They are also known as thief ants because they build nests near shelters of other ants and steal their food, larvae, and pupae. Due to their smaller size, they can fit anywhere. 

Grease ants forage in large numbers and leave pheromone trails behind for other grease ants to follow. They mostly infest houses during the summer season. Grease ants are commonly confused with Pharaoh ants due to their tiny appearance.


Grease ant queens and drones have wings that help in the breeding process. They mate from July to late fall. Queens can lay up to 387 eggs each day. Eggs develop into adults in about 7 to 8 weeks. The newly hatched ants have lighter bodies that later turn darker (in 2 days) due to the deposition of chitin and pigments.

What Does a Grease Ant Look Like?

What Does a Grease Ant Look Like

Worker greases ants have a yellow to light or dark brown appearance and measure between 1.5 to 2.2 mm (or up to 1/16 inch). They have a smooth and shiny body, six legs, an oblong abdomen, small compound eyes, and uneven thorax without spines. Antennae are divided into 10 segments, which end with bi-segmented antennal clubs.

The thief ants curl their body when they die. Grease ants are polygynous, which means they have up to eight queens (about 5 mm long) in each colony. The queen has a relatively thicker body and a large abdomen. Like other ants, they also have a caste system that includes queens, reproductive males, and workers.

Are These Ants Attracted to Grease?

Grease ants are omnivorous and can eat anything including meat, honeydew-producing insects, fungal spores, dead animals, larvae, and pupae of host ants.

These ants travel a long distance in search of food and are attracted to your house mostly due to different food sources. They can eat both sweet and greasy food but prefer to feed on greasy foods such as olive oil, vegetable oil, peanut butter, fats, nuts, seeds, cheese snacks, dairy products, etc.

Do Grease Ants Bite?

Grease ants are not considered to be a potential threat, they do not bite or sting. Although, the well-established colonies of grease ants can be annoying. Due to their smaller size, they can infiltrate food containers and packages and can ruin them.

As thief ants also feed on dead organisms, they can carry pathogens into your house and cause diseases like diarrhea, fever, or vomiting. Grease ants are the intermediate hosts for poultry tapeworms as they have the potential to carry tapeworm segments into their shelters.

What Kills Grease Ants?

Several ant killer sprays and baits are available commercially for getting rid of grease ant colonies. Professionals mostly use insecticide sprays, baits, or integrated pest management plan to control pests. However, ant baits or ant traps are considered to be the most effective ant killers.

The method with ant baits takes time but it kills the entire ant colonies including queens which eliminates the chances of re-infestation or survival of the colony. Other than commercial ant killers, natural or DIY homemade ant killers can also help to get rid of grease ants.

Sugar Ants vs Grease Ants

The primary difference between sugar ants and grease ants is their distinct behavior towards different food items. Sugar ants include a group of ants known for their fondness for sugar or sugar-based food items such as jams, jellies, cakes, juices, etc whereas grease ants (also called proteins ants) like to eat grease-based or high-protein food items.

Grease can also eat sugar-based food but they give preference to greasy food. Both of them are common household ants and are easily drawn to residential settings by following the food trails.

How to Get Rid of Grease Ants | Instructions

Grease ants’ extermination can be a very troublesome process especially when they invade your house or pantry. Their tiny size allows them to build nests in small cracks and other inaccessible areas.

In the following section, we have given a step-by-step guide for getting rid of grease ants and some additional tips on preventing their re-infestation.

Step 1: Ant Identification

Accurate identification of particular pests plays a key role in pest control. Grease ants are often confused with Pharaoh ants due to the similarity in their size. The characteristics that distinguish Pharaoh ants from grease ants are different markings and body colors. 

Pharaoh ants have three clubbed antennae whereas grease ants have two clubs on their antenna. Grease ants have a yellowish to brownish color, whereas Pharaoh ants have a reddish body with black markings at the abdomen.

Step 2: Inspection of Infested Sites

The next step is the inspection and investigation of infested sites. Look for small ants on your kitchen counters, cabinets, ants foraging on the floor, or near oil traces.

Grease ants build nests at remote and inaccessible sites and travel far from their nests for food. Follow their trails and monitor their nesting sites so you can, in the end, treat those areas with insecticide.

Step 3: Application of Insecticides

The selection of the best insecticide for the infestation at a particular site determines the end results. The pest control method suitable for indoor infestation may not work for outdoor grease ant eradication and the other way around.

Related: Do Dead Ants Attract More Ants? | The Play-Dead Phenomenon!

Indoor Pest Control | Ant Bait for Grease Ants

Use ant bait or ant traps for indoor eradication of grease ants. Find ant trails and their nesting sites and place the baits near trails, nests, and nearby access points of ants.

Some of our recommended baits for grease ants are:

Sale 1
Syngenta - TRTD11568 - Optigard Ant Bait Gel Box - 4 Tubes w/ Plunger - 30g each tube, White
  • Target pests: For indoor and outdoor control of...
  • Highly attractive formula promotes ready transfer of the active...
  • Powerful, active ingredient knocks out workers, brood and queens
  • Approved for use indoors and outdoors, applied in cracks and...
  • How does Optigard Ant Bait Gel work? Ants that feed on the gel...
Amdro Ant Killing Bait Indoor Stations, No Size, None
  • Stake into soft ground or lay flat on hard surfaces
  • Kills sweet and grease eating ants (except Carpenter, Fire,...
  • Starts working immediately. Includes adhesive strips for...
Nisus Dominant Ant Bait Liquid Borate Ant Poison,(0.473 liters), Packaging May Vary
  • Kills most common household ants
  • Indoor and outdoor use
  • No foul odors
  • Super-sweet bait lures ants quickly
  • Easy application, just apply near trailing ants
Sale 4
PIC Plastic Ant Killer Bait Stations, Effective Ant Control Traps, 4 Pack (16 Traps Total)…
  • For indoor and outdoor use
  • 16 child-resistant baits
  • Starts killing ants within 24 hours
  • Kills Sweet & Grease Eating Ants, Pavement Ants, Odorous Ants and...
  • Not for use against: Fire Ants, Harvester Ants, Pharaoh Ants,...
Sale 5
TERRO T1812SR Outdoor Liquid Ant Bait Stakes-2 Pack
  • Attracts & Kills – Kills common household ants including...
  • Kills the Ants You See & the Ones You Don't – As worker ants...
  • Works Fast – You should see a significant decrease in the...
  • Ready to Use – Insert stakes and break the tab, then watch it...
  • For Outdoor Use – Place the bait stakes in outdoor areas where...

Outdoor Pest Control

To treat the outdoor nesting sites, locate outdoor nests and ant trails to decide the required quantity of control solution or spray.

Directly treat the nests or infested sites with insecticide chemicals to eliminate grease ants. Remember to wear personal protective equipment (PPE) to avoid direct exposure to insecticide chemicals. Read the labels and follow product guidelines on the spray for effective pest control.

Some of the best insecticide sprays or control solutions for grease ants are the following:

Stem Kills Ants, Roaches And Flies: Plant-Based Active Ingredient Bug Spray, Botanical Insecticide For Indoor Outdoor Use; 12 fl oz (Pack Of 1)
  • Spray that quickly slay ants, roaches and flies
  • Plant-based active ingredient bug slayer safe for use around...
  • Entomologist tested insect spray made with botanical extracts;...
  • For indoor and outdoor use, wherever insects try to bother you
  • Rooted in Nature, Optimized by Science​
Ant Killer Indoor Safe for Pets and Kids (16oz) by Kate's Home & Garden. Roach & Ant Killer Spray for Indoor & Outdoor. Insecticide for Ants and Roaches with Natural Cedarwood Oil
  • CHILD AND PET-SAFE SPRAY: Can be slippery on floor. Make sure to...
  • REPELS ANT AND ROACH WITH CEDARWOOD OIL: Repels roach, ant and...
  • NATURAL INGREDIENTS: Made with natural ingredients and...
  • NATURALLY EFFECTIVE. KILL ON CONTACT. Protect against ants and...
Sale 3
Raid Ant & Roach Aerosol Bug Spray, Water-Based Formula Insecticide with No Greasy Residue, Kills On Contact, 17.5 oz
  • Raid Ant & Roach Aerosol Bug Spray kills a wide variety of...
  • Water-based formula bug killer spay leaves no greasy residue
  • Fragrance Free / no lasting odor Ant & Roach insect spray
  • Apply on indoor surfaces every 4 weeks as necessary to maintain...
  • Raid Defense System protecting families from bugs for more than...
Mighty Mint - 16oz Natural Peppermint Oil Ant Killer and Repellent Spray - Safe for Indoor/Outdoor Use
  • Safe around People and Pets
  • Natural Ingredients
  • Highly Effective Contact Kill and Repellent
  • Powerful Fresh Mint Scent
  • Works for All Types of Ants
Hot Shot Ant, Roach & Spider Killer Spray, Kills Roaches and Listed Ants on Contact, Indoor & Outdoor Use, Insecticide Spray, 17.5 Ounce (Lemon scent)
  • FAST KNOCKDOWN: Kills listed insects on contact and keeps on...
  • KILLS INSECTS INDOORS: Controls ants (excluding harvester ants),...
  • KILLS INSECTS OUTDOORS: Kills ants, cockroaches, spiders, fleas,...
  • LEAVES NO OILY RESIDUE: Dries quickly without leaving behind an...
  • FRAGRANCE FREE: Controls insects while leaving behind a fresh...

If you really want to kill ants even in a wider radius the best thing would be to combine insecticide sprays with ant baits. Monitor treated sites for 10 days and re-apply ant killers if needed. Take preventive measures to stop the re-establishment of grease ant colonies.

Step 4: Preventing Re-infestation

Remove all the factors that are attracting grease ants in your house or garden such as excess water, spilled food, leftovers, etc. Keep the kitchen floor and counters clean and do not leave the garbage overnight.

Tightly seal food containers, packages, and store them in the refrigerator. Clean pet feeders and pantries regularly. Seal all the cracks and holes that can be potential nesting sites of grease ants and apply sweeps, petroleum jelly, or caulk at the access point of ants.

Put ant-repellent herbs or pots (garlic, sage, cinnamon, lavender, tansy, peppermint, etc) around your house. They will help to erase the ant trails and will prevent their entry into your house.

Home Remedies for Grease Ants | Natural Methods

Other than commercial ant killers, DIY natural insecticides can also help in the eradication of grease ants. This is an economical, eco-friendly, and non-toxic way to get rid of these pests. In the following section, we have shared the best DIY grease ant control remedies. Let’s begin!

Peanut Butter and Borax Bait

Peanut butter and borax bait can effectively eliminate grease ant colonies. To prepare peanut butter bait, take two teaspoons of peanut butter and mix it with four teaspoons of borax to make a paste.

You can also add honey to the paste for better results. Put the bait in a disposable container and place it near ant trails and nearby nests. If you want you can also stick these baits on the wall or cabinets with the help of tape.

Vinegar and Water

To make insecticide spray, mix equal parts of vinegar and water (1:1). Pour the solution into a spray bottle and directly apply it at the potential nesting areas and on the kitchen counters. This does not only kill ants but also keeps them away.

Soap and Water

Soapy water is a natural insecticide, it can help to exterminate grease ants and several other pests. To prepare soapy water, take one part of dishwashing soap and mix it in two parts of water (1:2). Pour the solution into a spray bottle and treat the infested areas and access points of ants. Adding hot water to the soap can enhance the efficiency of this insecticide solution.

Peppermint Spray

Peppermint spray is a natural ant killer and repels the re-establishment of ants and other pests. To prepare peppermint spray, add 10 to 20 drops of peppermint essential oil in 2 cups of water and mix them together.

Mighty Mint - 16oz Natural Peppermint Oil Ant Killer and Repellent Spray - Safe for Indoor/Outdoor Use
  • Safe around People and Pets
  • Natural Ingredients
  • Highly Effective Contact Kill and Repellent
  • Powerful Fresh Mint Scent
  • Works for All Types of Ants

You can also put a few drops of citrus oil or tea tree oil to increase the effectiveness of the spray.

List of Sources

Extension and Outreach, Horticulture and Home Pest News, (2005). Grease Ants, Iowa State University of Science and Technology.
Plant & Pest Diagnostics, Thief ants, University of Arizona and Michigan State University.
Extension and Outreach, Horticulture and Home Pest News, (2005). Grease Ants are Still a Problem, Iowa State University of Science and Technology.
Davis, (2011). Thief Ant – Quick Management Tips. UC IPM, Key to identifying common household Ants, University of California Agriculture and Natural Resources.

Thomas Matthews
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