Ants Around the Home and Landscape
by Jody Green, Extension Educator
When people contact our office about ants in and around their house they are:
- Large ants
- Regular ants
- Teeny tiny ants
Entomologists have different ways to identify ants and they can be split up into food preference (sugar, sugar and protein, grease), number of nodes on petiole (one or two), behavioral patterns (tramp ants/invasive species), nesting preference and other seemingly odd characteristics. It is always good to have as much information about your ant as possible.
Ants are usually identified by their segmented body, even people with little entomological background can see a waist or constriction between body parts: the head, thorax and abdomen. They also possess a pair of elbowed antennae. Resources:
All ants are social, which means they live in colonies in a caste system, where they function as a superorganism working for the good of the colony. All ants undergo complete metamorphosis and go through four stages of development: egg, larva, pupa and adult. Rarely are the eggs, larvae and pupae seen unless the nest is revealed and many adult/workers (all female) ants will quickly pick them up and move them to safety because they have no means of locomotion on their own. Queen ants are egg-laying machines for the entire colony. Seasonally/ annually, winged forms of male and female ants will emerge from the nest, find a mate, and disperse as a way to increase genetic diversity and begin new nests.
Common Ants in Nebraska
Carpenter ant (Camponotus spp.)
- Nickname: Big black ant
- Identification: Evenly rounded thorax, hairs on abdomen, one-node petiole, can be a variety of colors including black and red and black, nocturnal.
- Importance: Wood destroying insects that excavates galleries in wood but does not consume the wood. Often a household nuisance when found foraging indoors. Can live indoors all year round and seen outdoors during the warmer months. Can forage 100 ft or more for food so nest may not be on your property.
- Nests: In live and standing trees, in firewood and logs, in lumber in human structures
- Feeding preference: Sugary foods and protein foods, which include other insects.
- Signs of damage: Coarse sawdust kicked out galleries with insect body parts, insulation, or other materials. Sometimes there is a crunching sound behind the walls. Presence of carpenter ants often reveal a hidden moisture problem within the structure like a faulty window or skylight, improper grading, appliance leaks.
- Trick: Must locate the nest and take care of the entire colony to eliminate them from the building. To stop them from foraging inside, seal up holes and stop highways leading to your house like hoses, electrical wires and tree branches.
Citronella ant (Lasius interjectus)
- Nickname: Yellow ant
- Identification: Yellow color, one-node petiole, smells like lemon verbena or citronella when threatened or crushed, winged ants seen indoors swarming.
- Importance: Swarms indoors any time of year, particularly in winter months in Nebraska when they become a nuisance for a few days.
- Nests: Nest outdoors in the soil, under vegetation, rocks, logs, and under slab, rarely seen unless swarming.
- Feeding preference: Aphid honeydew.
- Signs of damage: Swarmers are large and have black, smoky wings, their bodies can vary in color. Often surprise people by swarming in the winter months, coming up out of cracks in the slab.
Odorous house ant (Tapinoma sessile)
- Identification: Workers are 1/8-inch long, black color, one-node petiole that is hidden under gaster, emits smelly odor (rotten coconut/blue cheese) when crushed.
- Importance: Common ant that nests indoors close to people, especially in the spring.
- Nests: Can be found indoors under sinks and appliances or outdoors along the foundation under rocks and items in the garden.
- Feeding preference: Sugary foods, especially liquid.
- Signs of damage: Odorous house ants have steady well-defined trails that come from outside, entering a crack in the structure into kitchens.
- Trick: A steady buffet of a liquid sugar bait.
Pavement ants (Tetramorium immigrans)
- Nickname: Sidewalk ants, cement ants
- Identification: Workers are 1/8-inch long, reddish-brown-black, two-node petiole, two spines on thorax, ridges on head and thorax.
- Importance: Ants are often found in large numbers on the sidewalk and driveway and seem to find a food crumb or drip the minute it falls to the floor, especially in the spring and summer.
- Nests: Under slab, bricks or pavement but also grassy areas near sidewalks. They excavate soil from underground and form mounds in the cracks.
- Feeding preference: Sugary foods and greasy foods, anything people have in the kitchen, dead invertebrates, pollen and garbage.
- Signs of damage: Pavement ants are very territorial and have epic battles with neighboring colonies for territory by the hundreds of thousands. Ants will be fighting intensely for hours and then disappear by the next day, taking their wounded back to their nest.
Thief ant (Solenopsis molesta)
- Nickname: Grease ant, teeny tiny ant
- Identification: Workers are 1/16-inch long, orange-brown color, two-node petiole, 2-segmented club antennae.
- Importance: Often noticed when there are plenty on the kitchen counter.
- Nests: Nest around human structures, forests, grassy areas, close to other ants. Can live in microhabitats indoors without being detected in pumps, motors, and pantry.
- Feeding preference: Feeding preferences: prefer grease and protein, like dead insects and larvae of other ant colonies.
- Signs of damage: Thief ants are super small that they tend to go unnoticed unless they are on a light background or found in food products in the pantry.
- Additional Resources:
Field ant (Formica pallidefulva)
- Identification: Variety of colors, one-node petiole, uneven thorax, long, stretched out body, long antennae and legs.
- Nests: Large mounds built in the open away from trees, disturbed areas, like prescribed burn prairies, but also in yards.
- Feeding preference: Sugary foods, aphid honeydew, other insects like caterpillars, seeds.
Cornfield ant (Lasius neoniger)
- Identification: Light-dark brown, round abdomens, stubby bodies, one-node petiole.
- Nests: Open areas, grassy areas, golf courses, under trees that look like mini, flattened volcano mounds with many entrances.
- Feeding preference: Aphid honeydew.
- Signs of damage: Mounds outside.
Acrobat ant (Crematogaster lineolata)
- Identification: Black, 1/8-long, heart-shaped gaster raised above body when disturbed, two-node petiole, two spines on thorax.
- Nests: Under bark, rotting wood, logs, forest floor, sometimes forage near homes and structures if moisture damage.
- Feeding preference: Aphid honeydew, dead insects.
- Signs of damage: If in the house can kick out frass that looks like carpenter ant frass (saw dust, particles, insulation). Will trail in long lines for a great distance.
Management of Ants
The majority of ant species, regardless of whether you find them inside the home or not, will actually be nesting outdoors. Signs of frass, soil particles, insulation, wood shavings or sawdust indicate ants nesting inside the home and is an indication that there is a more significant structural or moisture problem and should be investigated more thoroughly. Treatment of the nest to eliminate ants and repair of the structure to prevent reinfestation is recommended.
Ants require what all living things require to survive: food, water, and shelter. In order to keep them away from human food and homes, we need to practice good sanitation and storage of our food products. Ants are masters when it comes to finding crumbs, drips and drops of sugar, so be quick to clean up spills off floors, desks and countertops so they do not have time to find food and summon nestmates to join the party.
Ants foraging from outside, come indoors through cracks and crevices and other small entry points. It is important to deter these trails, seal up the gaps with caulking or sealants, and provide an attractive, palatable bait for them as close to outside walls as possible. Baits must be placed in areas where ants frequent so they can be found and taken back to the nest to be shared with the colony. Baits are slow-acting so they allow transfer of the toxicant to colony members. Once a baiting program is started, that ants are allowed to forage freely so they can use their social behavior to eliminate the colony. It can take 24 hours up to several weeks for a bait to be successful, consider a variety of formulations and locations, and be patient.
It is important to note that ants are social insects and have colonies with individuals numbering hundreds of thousands. Stepping on or spraying foraging ants that enter the home will have no effect on the overall health of the colony. It is best to have your ant species identified so you can choose the control method that will be most time and cost effective.
Over the Counter Ant Insecticides
* indicates the product can be used for carpenter ants
Liquid Bait (usually sugar) can be used indoors or outdoors according to the label where ants can come and feed, and then take toxic bait back to the colony.
- Terro Liquid Ant Bait/ Terro Outdoor Ant Bait Stakes (A.I. Boric Acid 5.40%)
- Spectracide Ant Shield Outdoor Killing Stakes (A.I. Indoxacarb 0.05%)
- Amdro Kills Ants Ant Killer Liquid Bait Stations (A.I. Boric Acid 5.4%)
- Hot Shot Ultra Liquid Ant Bait (A.I Dinotefuran 0.05%)
Bait Stations are ready-to-use, pre-packaged plastic stations where ants can come feed and then take toxic bait back to the colony.
- Raid Ant Bait III (A.I. Avermectin 0.01%)
- Raid Double Control Ant Bait II (A.I. Avermectin 0.05% Protein, Sugar)*
- Raid Ant Gel (A.I. Thiamethoxam 0.003%)*
- Raid Max Double Control Ant Bait (A.I. Avermectin 0.05%)*
Granule Bait can be applied outdoors so that foraging ants can pick them up and take them back to the colony.
- Terro Perimeter Ant Bait Plus/ Terro Multi-Purpose Insect Bait (A.I. Boric Acid 5%)
- Amdro Ant Block Home Perimeter Ant Bait Granules (Granule A.I. hydramethylnon 0.88%)
Granule Insecticidecan be applied outdoors and act as a residual, contact insecticide.
- Terro Ant Killer Plus (Shaker Bag Granule A.I. Lambda-Cyhalothrin 0.04%)
- Spectracide Ant Shield Home Insect Killer Granules (Granule A.I. Lambda-Cyhalothrin 0.04%)
- Ortho Home Defense MAX Insect Killer Granules (Granule A.I. Bifenthrin 0.115%)
- Amdro Quick Kill Lawn Insect Killer Granules (Granule A.I. Bifenthrin 0.1%)
can be applied according to the label as residual, contact insecticide.
- Spectracide Ant Shield Home Insect Killer Ready-to-Use (A.I. Lambda-Cyhalothrin 0.03%)
- Ortho Home Defense Insect Killer (A.I. Bifenthrin 0.05%, Zeta-Cypermethrin 0.0125%)
Dust can be applied to the nest of ants.
- Terro Ant Dust (Dust A.I. Deltamethrin 0.05%)
Summary of Over the Counter Active Ingredients:
- Bifenthrin & Zeta Cypermethrin
- Boric Acid
Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the University of Nebraska–Lincoln is implied. The information on this Web site is valid for residents of southeastern Nebraska. It may or may not apply in your area. If you live outside southeastern Nebraska, visit your local Extension office