How to Get Rid of Grease Ants: A Complete Guide

Grease ants are one of the most persistent indoor and outdoor pests, also referred to as thief ants due to their capability to steal food from other ants. They prefer protein-rich and greasy foods such as meat, cheese, peanut butter, oils, dairy products, etc. They can readily adapt to different environments and build their colonies wherever they find favorable conditions.

Larger colonies of grease ants can cause serious problems and are really hard to eliminate. Therefore, you should have a clear idea about how they behave in order to design an effective ant extermination plan.

How to get rid of grease ants? To get rid of grease ants you first need to remove any food sources and other grease ant attractants in your house. Next, inspect the level of infestation and select one of our methods for getting rid of grease ants such as ant baits, insecticide sprays, and dust. After eradication, monitor the treated area to avoid re-infestation.

In the following section, we have provided a comprehensive guide for getting rid of grease ants. Further, we will discuss factors that contribute to grease ant invasions and you will also find our step by step guide on how to eradicate grease ants from your premises. Let’s begin!

Grease Ants | Information

Grease ants or thief ants are native to the United States and are commonly found all over the Eastern, Western, and Central regions of the U.S. They are also reported in Northern Mexico, Southern areas of Canada, California, Mississippi, Illinois, Texas, and North Dakota. These ants have great potential to survive in harsh environmental conditions.

Being one of the tiniest pests, grease ants can establish their colonies anywhere in residential areas such as in cracks, holes, under sinks, behind cabinets, cupboards, and other small openings. Outdoors, grease ants build shelters under rocks, ground soil, under the wood shavings, beneath rotten wood, or wherever they find favorable conditions.


What Are Grease Ants?

Grease ants belong to the genera Solenopsis, 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.


Reproduction

Grease ant queens and drones have wings which 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, 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 queen, 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 eliminate 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 ant’s 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 ant due to similarity in their size. The characteristics that distinguish Pharaoh ants from grease ants are different markings and body color. 

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’s eradication and the other way around.


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:

TERRO T300 Liquid Ant Bait

TERRO T300B Liquid Ant Killer, 12 Bait Stations
  • 12 bait stations included
  • Kills all common household ants
  • Pre-filled, ready-to-use bait stations
  • Patented design prevents bait from drying out
  • Attracts ants fast

PIC Homeplus Ant Killer Bait

Sale
PIC 4PK AB Homeplus Ant Killer Metal Bait Stations, 4 Count, Multicolor
  • for indoor and outdoor use
  • "package length :3.81"""
  • "package width :11.94"""
  • "package height :13.97"""
  • Power source type: Manual

Combat Ant Baits

Combat Ant Baits 6 / Box
  • Combat Ant Bait Insectiside
  • Kills Ants - 0.21 oz (0.01 lb) - Black, Silver
    Insecticide...
  • Combat 45901

Optigard Ant Bait Gel Box

Sale
Syngenta - TRTD11568 - Optigard Ant Bait Gel Box - 4 Tubes w/ Plunger - 30g each tube
  • 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...

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:

Cutter Backyard Bug Control Spray Concentrate

Cutter Backyard Bug Control Spray Concentrate (HG-61067) (32 fl oz) (2 Pack)
  • Repels and kills mosquitoes and other annoying insects
  • Controls up to 4 weeks, even after rain
  • 32oz treats up to 5,000 sq ft

Raid Ant and Roach Barrier Spray

Raid Ant & Roach Barrier Spray, Killer for Listed Bugs, Insect, Spider, For Indoor & Outdoor Use, 22 Fl Oz, Pack of 1
  • Keeps ants, fleas, flies, gnats, roaches, ticks silverfish,...
  • Leaves no lingering odor
  • For indoor and outdoor use
  • Raid Ant & Roach Barrier lays down a line of defense to keep ants...

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 on 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 keep 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 in 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.

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


Summary

Grease ants are also known as thief ants due to their habit of stealing food from neighboring ant nests. They can eat everything but prefer high protein, grease, or oil-based food items. Grease ants are one of the tiniest ants on earth which makes their eradication more difficult. They can fit everywhere and can establish colonies inside inaccessible cracks and holes in indoor and outdoor settings. 

Poor sanitary conditions and food can attract grease ants overnight in your house. Grease ants are often confused with Pharaoh ants due to their similar size. Accurate identification of the ant species helps to effectively get rid of them. To exterminate grease ants, you first need to inspect nesting sites and follow ant trails to select an effective ant eradication method we mentioned above. 

In case you are having a serious ant infestation, it would be best to call a professional pest control service. Click on the following link if you are interested, and you will get free quotes from the best ant exterminators in your area. Best of luck!


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.