How To Identify the Most Common Ants and Their Mounds in Austin
Ants are small, but they work together and they make up for it in numbers. Knowing which ant you have, and what its nest looks like, is the quickest way to get ahead of an infestation instead of chasing trails around the kitchen.
Look at the ant first. Then look at where it lives.
Before you treat anything, spend a minute watching. How big are the ants, and are they all the same size? What colour are they? Where is the trail coming from and going to? Is there a mound, a crater of fine dirt, or no nest in sight at all? Those answers narrow a dozen possible species down to one or two, and the right treatment follows from the species. A product that clears one ant will scatter another into three new nests.
Austin has more ant species than any homeowner wants to learn, but a handful account for nearly every call we take. They are described below, along with what their nests look like and what to do about each. If you would rather skip the identification, our Austin pest control technicians do it on every visit, and a clear photo sent with your request helps.
The seven ants you are most likely to find
Several sizes, several colours, and very different nesting habits. Here is how to tell them apart.
Acrobat ants
Small, light brown to black, with a heart-shaped abdomen they raise over their head when disturbed, which is where the name comes from. They nest in moist or previously water-damaged wood, so look for them around window frames, door frames, baseboards, and wall voids near a leak. Outdoors they trail along utility lines and tree limbs into the house.
Carpenter ants
The largest ants you will see around an Austin home, up to half an inch, black or black and red. They hollow galleries in wood to nest, favouring wood that is already damp. Signs include small piles of coarse sawdust under window sills or trim, a faint rustling inside a wall at night, and trails of large ants at dusk. The sawdust is mixed with insect parts and waste, and it is dry and fibrous, not the hard pellets termites leave.
Red imported fire ants
Reddish brown with a darker abdomen, an eighth to a quarter inch long, with workers of several sizes in the same colony. They build the dome-shaped dirt mounds that dot Austin lawns, especially after rain, and they boil out and sting as soon as a mound is touched. Indoors they go for greasy and sweet foods and pet food. Their sting is covered further down.
Little black ants
Tiny, about a sixteenth of an inch, jet black and shiny. Outdoors they nest in soil under rocks, logs, and pavers, leaving a small crater of fine dirt. Indoors they nest in wall voids and under flooring, so you see trails rather than a mound: thin lines of ants running along a counter edge or a baseboard to a crumb or a drip.
Odorous house ants
Brown to black and an eighth of an inch long, named for the rotten-coconut smell they give off when crushed. No mound. They nest in shallow spots under rocks, logs, mulch, and potted plants, and inside walls near warmth and moisture. Colonies move readily when disturbed, which is why a spray that scatters them tends to produce two trails a week later.
Pharaoh ants
Very small, pale yellow to light brown with a darker tip to the abdomen, and almost entirely an indoor ant in Texas. They nest in cracks, wall voids, behind baseboards, and inside appliances where it is warm, and a colony splits into new ones when stressed. There is nothing to see outdoors. Indoors you see slow-moving trails to water and sweet or fatty foods.
Rover ants
Tiny dark ants, often mistaken for little black ants, that have become one of the most common house invaders in central Texas. They nest in rotting wood, leaf litter, mulch, and potting soil close to the foundation and come inside in warm weather for sugar and moisture. You will find them in kitchens and bathrooms rather than along exterior walls.
Reading the nest from the outside
Only one of the common Austin ants builds a mound you would call a mound. A red imported fire ant colony pushes up a dome of loose, crumbly soil, anywhere from a few inches to a foot across and taller after a rain, and the quickest way to confirm it is to look at the top. There is no central hole. Fire ants enter and leave through tunnels that open at the sides and underground, so the dome is smooth and closed. Nudge it with a stick and workers pour out within seconds. Mounds show up in open sunny lawn, along sidewalks and driveways, at the base of trees, and against the slab, and new ones appear after every heavy rain as the colony moves up out of saturated soil.
Little black ants leave a small, flat crater of very fine soil with an open hole in the middle, usually at a crack in a sidewalk or next to a paver. Odorous house ants and rover ants have no visible nest at all; lift a stepping stone, a flower pot, or a rotting board along the foundation and you will find the colony underneath. Acrobat ants, carpenter ants, and pharaoh ants nest in wood or in the structure itself, so what you see is the trail and, for carpenter ants, the sawdust below the nest.
If there is no mound, that is itself a clue. Trails of small ants inside a house with nothing in the yard point to one of the indoor nesters, and the fix is to find and treat the nest rather than to wipe out the trail.
What a fire ant sting does
Fire ants grip the skin with their jaws and sting with the tip of the abdomen, often several times, and a disturbed mound produces dozens of stings in a few seconds. The sting burns immediately, which is where the name comes from. Within a day or so each sting raises a small white pustule that itches and lasts about a week; scratching it open is what leads to infection. For most people that is the extent of it.
A small number of people have a severe allergic reaction to fire ant venom, with swelling beyond the sting site, hives, trouble breathing, or dizziness. That is a medical emergency and needs emergency care right away. Anyone who has reacted that way before should treat every mound in the yard as a hazard and have it dealt with. Our red fire ant page covers the species and how we treat it.
Two things every homeowner can do
Ants come for food, water, and shelter, and they get in through gaps. Take those away and most trails never start.
Make your home less attractive to ants
If ants find reliable food and water around a house, they move the colony closer to it. Remove the reasons to come.
- Store food in airtight containers or the refrigerator, including pet food.
- Trim shrubs and tree limbs back from the walls and roofline so they are not a bridge into the house.
- Fix dripping faucets and hose bibs and clear clogged gutters so there is no standing water near the foundation.
- Wash pet dishes after each meal rather than leaving them down.
- Water the lawn only as much as it needs. Soggy ground along the slab is ant habitat.
- Pull mulch back from the foundation and keep it shallow.
Make your home less accessible to ants
A house gives ants shelter where predators cannot follow. A few simple repairs close the doors they use.
- Seal exterior cracks, gaps, and holes around the foundation, utility penetrations, and weep holes with an exterior-grade sealant.
- Add or replace weather stripping around windows and doors so the sweep meets the threshold.
- Install or repair window and door screens.
One caution on retail sprays. Odorous house ants, pharaoh ants, and several others respond to a repellent spray by splitting the colony, so a trail wiped out on Monday becomes two or three by Friday. Where ants are already nesting indoors, a bait the workers carry back to the nest does more than any spray along the trail, and matching the bait to the species is the part that takes experience.
Know the ant, treat the nest
Carpenter ants damage wood, fire ants sting, and the indoor species carry what they walk through onto your counters. Our Austin technicians identify the species, find the nest, and treat it with the product and method that fit, as part of Integrated Pest Management that targets the problem rather than the whole house.
Keep reading
The Red Imported Fire Ant
Aggressive, quick to rebuild, and all over Texas. What you need to know about red fire ants and how to control them.
Read articleAntsWhat Are Pheromone Trails and How Do Ants Use Them?
How ants lay, strengthen, and lose scent trails, the other messages a colony sends by pheromone, and why that makes baits work where sprays fail.
Read articleTermitesSigns of Termites & What To Do About Them
Termite infestation is a common problem in the US, with more than 600,000 homes affected yearly. Here are the signs of termites to watch out for.
Read articleGot a pest problem? Get a free quote today.
Tell us what's going on and get a free, honest quote over the phone. No inspection fee, no obligation. Same-day service in most cases, and every visit is backed by our 100% satisfaction guarantee.
Call (281) 972-4612Free quote · Same-day in most cases · 100% guaranteed
Rated 4.7/5 from 126 Google reviews
Get a free quote
Step 1 of 3What's bugging you?
Free quote · No obligation · 100% guaranteed
4.7/5 from 126 Google reviews
Prefer to call? (281) 972-4612