Ghost Ants: Identification and Why Sprays Make Them Worse
Ghost ants are tiny tropical ants, 1.3 to 1.5 mm long, with a dark brown head and thorax and a pale, milky abdomen and legs, so the front half seems to float across the counter. They do not sting and are a nuisance rather than a danger. In the US they live outdoors mainly in Florida, Hawaii and parts of Texas, and survive elsewhere only in heated buildings. Colonies have many queens spread across many small nests, which is why spraying the ants you see rarely ends the problem and slow sweet baits usually do.
The University of Florida describes the ghost ant as a nuisance that was only an occasional house pest in Florida as late as 1988, and a major pest by 1995. In a survey of Florida structural pest control staff, it was one of the three most common ants in samples, each making up 14 per cent. If you live in central or south Florida and see a trail of almost invisible ants at the kitchen sink, this is the most likely candidate.
Ghost ant identification
Two features identify a ghost ant: its size and its two-tone colour. The University of Florida’s Featured Creatures profile gives workers as 1.3 to 1.5 mm long, all one size, with a deep dark brown head and thorax and an opaque or milky white gaster and legs. The small size and pale colour together make them hard to see, which is where the name comes from.
| Ghost ant | Pharaoh ant | Odorous house ant | |
|---|---|---|---|
| Worker length | 1.3 to 1.5 mm (about 1/16 inch) | 1.5 to 2 mm (about 1/16 inch) | 2.4 to 3.3 mm (1/16 to 1/8 inch) |
| Colour | Dark brown head and thorax, pale milky abdomen and legs | Yellowish or light brown to red, abdomen often darker | Uniform brown to black |
| Waist (nodes) | One, hidden under the abdomen | Two | One, hidden |
| Stinger | None | Present, rarely used | None |
| Queens | Many, spread across subcolonies | Up to several hundred in large colonies | Many |
| Where in the US | Outdoors in Florida, Hawaii, parts of Texas; indoors elsewhere | A major indoor pest across the US | Native to most of the US |
| Usual bait | Sweet liquid | Protein, fats and sweets | Sweet |
Ghost ant and pharaoh ant details are from University of Florida profiles EENY310 and EENY290; odorous house ant details are from Penn State Extension; pharaoh ant food preferences are from UC IPM. Crushed ghost ants smell like rotten coconut, UF notes, and Penn State describes a rotten odour as distinctive of the odorous house ant.
UF notes that the ghost ant shares a genus with the odorous house ant but is smaller and coloured differently, and that the pharaoh ant, the other common tiny indoor ant, has two nodes in its waist where the ghost ant has one. For other small ants, our ant identification guide walks through the waist and size checks, and our sugar ants guide covers the several species that get that nickname, ghost ants among them.
Are ghost ants harmful?
Not to people directly. UF records that stingers are absent, and none of the extension sources we read describe ghost ants biting people. They are a household nuisance: UF calls the species one of the most important ant pests in Florida homes, because it can both invade from outside and nest indoors.
Are ghost ants dangerous or can they make you sick?
The concern is contamination rather than injury. Studies in Brazilian hospitals have repeatedly found ghost ants among the most common ants indoors and carrying bacteria. A 2026 study in a hospital in Maceió found ghost ants among the two most prevalent species, with bacteria including Escherichia coli on ants from 10 hospital areas, some resistant to several antibiotics. An earlier study at a university hospital in Uberlândia found ghost ants carrying staphylococci, including drug-resistant strains. These studies show ants can carry bacteria on their bodies; they do not show that ghost ants in homes make people ill. Throw away food that ants have got into, and for any health concern speak to a doctor.
Are ghost ants bad for the garden?
Mixed. UF notes they tend honeydew-producing insects such as aphids, which can protect plant pests, but also that the ghost ant is a significant predator of the twospotted spider mite in greenhouses, and was found to be the primary predator of the eggs of a Chagas disease vector in coastal Venezuela.
Do ghost ants bite you?
Bites are not a recognised problem. Ghost ants have no stinger and are among the smallest ants found in homes, and the UF and Texas A&M sources we used do not list biting among their effects. If you are getting bitten indoors by something you cannot see, our bite identification guide is a better place to start than ghost ants.
What states have ghost ants?
UF reports that the ghost ant is well established in Florida and Hawaii and that its range is expanding. It reached Texas in 1994 or 1995, probably through Galveston on a shipment of plants from Florida. In northern states it can survive only in greenhouses and other heated environments. Within Florida it is mostly found from Sarasota to Orlando and south, though it occurs as far north as Gainesville and Duval County. Texas A&M adds indoor finds in cooler areas of Texas, Iowa and Oregon.
Our analysis of iNaturalist records shows the same pattern. Hawaii and Florida lead by a wide margin when sightings are scaled to each state’s total observations, Texas and Louisiana follow far behind, and every other state has only scattered records.
In raw numbers, the file holds 619 research-grade ghost ant records from Florida, 200 from Texas and 129 from Hawaii, against 13 from Louisiana and 13 from New York. A handful of records in a northern state fits UF’s description of ghost ants surviving in heated buildings and greenhouses there; it does not mean the species lives outdoors in those states. These are records of where people photographed and identified ghost ants, not a measure of infestation rates.
Why am I getting ghost ants?
Ghost ants come indoors for sweets and water, and they often arrive with plants. UF lists the reasons that matter most at home:
- Sweet food. UF notes a preference for sweets, with workers seen feeding on sugar, cakes and syrups, and they forage on sinks, counters and floors in kitchens and bathrooms.
- Moisture. UF advises reducing moisture sources, including condensation and leaks, as part of control. That is why bathrooms are a common place to find them; our guide to ants in the bathroom covers the water side of the problem.
- Plants touching the house. Ghost ants enter from nests near foundations or from plants in contact with the building.
- Potted plants. UF records nests in flowerpots and potted plants, and the species’ arrival in Texas is attributed to a plant shipment.
- Nests already inside. Indoors they nest in wall voids, between cabinetry and baseboards, in cracks and even between books.
Their diet changes with what the colony needs: outdoors, UF says, workers scavenge dead insects and collect honeydew. Our guide to what ants eat explains why a colony may take protein one month and sugar the next, which matters when a bait stops working.
Do ghost ants have queens?
Yes, many. UF describes moderate to large colonies with numerous reproducing females, broken into subunits in different nest sites that exchange workers back and forth along odour trails. New colonies are probably formed by budding, when one or more queens leave with some workers and brood for a new site, and members of different nests do not fight. Texas A&M adds that colonies move often and can form supercolonies. Ghost ants also nest opportunistically in places that may stay habitable for only days or weeks, which is why a colony is rarely in one place for long.
Why sprays make ghost ants worse
A spray kills the ants it touches. Texas A&M notes that contact insecticides can kill workers at a colony you find, but because a ghost ant colony may be spread across many nests, that only gives temporary relief. The surviving subcolonies keep foraging, and new ones form by budding.
The risk of actively making things worse is best documented in the pharaoh ant, which UF says has similar nesting habits. UF’s pharaoh ant profile warns that repellent products can cause the colony to fracture and bud, so activity drops for a while and then returns as the new colonies establish. Texas A&M points out that few studies have looked at ghost ant control specifically, so the same effect in ghost ants is an expert inference from that shared biology rather than a measured result. Either way, the advice points the same direction: put the sprays away and bait.
How do you get rid of ghost ants?
Texas A&M calls baiting the best management tactic, since ghost ants prefer sweets. The colony-level evidence comes from a 1996 laboratory study by Klotz and colleagues, which fed a 1 per cent boric acid sugar-water bait to colonies of three small household ants. Ghost ants responded fastest of the three. Bait strength matters as much as bait type, and our guide to borax for ants explains why weak boric acid sugar baits outperform strong ones.
In the same study, a hydramethylnon granular bait did not significantly affect ghost ant colony growth, which is a useful reminder that not every bait suits every ant.
| Control option | Where it goes | What the source says | Source |
|---|---|---|---|
| Sweet liquid boric acid bait | On active trails, near sinks and counters | A 1 per cent bait cut workers 97 per cent in a week and brood 96 per cent by week 3 | Klotz et al. 1996; Texas A&M |
| Hydramethylnon granular bait | Trails and nest areas | Did not significantly affect ghost ant colony growth | Klotz et al. 1996 |
| Contact or repellent spray | Visible ants and nests | Kills workers it touches; relief is temporary because the colony spans many nests | Texas A&M |
| Barrier treatment outdoors | Cracks, crevices and screens where foragers enter | Restricts foragers coming in from outside | UF EENY310 |
| Food storage and cleaning | Kitchens, pantries, counters | Store food in tight containers; any food particles attract ants | UF EENY310 |
| Moisture and plant fixes | Leaks, condensation, plants touching the house | Reduce moisture sources; ants enter from plants in contact with the building | UF EENY310 |
- Stop spraying and wipe visible trails with soapy water instead.
- Follow the trail back towards the nest if you can, as UF advises, and place bait along it.
- Use a sweet, slow-acting bait registered for ants, and follow the label. Enclosed stations keep it away from children and pets.
- Check within one or two days. UF says that if the ants are not feeding, move the bait.
- Keep bait available until trails stop, since the colony is spread across several nests.
- Remove competing food and seal it in tight containers, as UF recommends.
- Fix leaks and condensation, trim plants and branches touching the house, and check potted plants before bringing them inside.
Call a licensed professional if ghost ants keep returning in several rooms after a few weeks of correct baiting, if you live in a multi-unit building where the colony may span neighbouring homes, or if they are in a commercial kitchen. UF notes that foragers coming in from outdoors can be restricted with barrier treatments around the building, and UC IPM points out that professionals have access to materials and application equipment that homeowners do not.
Do ghost ants go away in the winter?
No, and this is one of the clearest differences from native ants. In our analysis of iNaturalist records, US ghost ant records hold steady at between 72 and 104 a month all year, while odorous house ant records fall from 1,848 in April to 145 in December. Because ghost ants keep being recorded while almost everything else drops out of winter records, their share of all observations, the index plotted below, is highest in December and January.
That fits what is known about the species: it is tropical and, outside the warmest states, lives in heated buildings. A study of 58 urban homes in Korea found ghost ants indoors all year, with indoor incidence peaking at 22.8 per cent in September and 15.7 per cent in May, moderate from October through April, and lowest from June to August at 7.0 per cent. Expect ghost ants to stay active indoors through winter if the colony is in your walls.
Frequently asked questions
Do ghost ants eat wood?
No. Ghost ants do not eat or tunnel through wood. UF records them feeding on sweets, honeydew and dead or live insects, and nesting in existing spaces: wall voids, gaps between cabinets and baseboards, potted plants, loose bark and the bases of palm fronds. If you find sawdust-like debris or large ants coming from wood, that points to carpenter ants or another pest, not ghost ants.
Do ghost ants jump?
No. Ghost ants do not jump. UF notes that workers run rapidly and erratically when disturbed, which can look like hopping because they are so small and pale. When they are trailing to food they move more slowly and deliberately, and some trailing workers can be seen carrying larvae and pupae, a sign of a colony moving to a new nest.
Do ghost ants like water?
Yes. Moisture is one of the things that draws them indoors, and UF advises reducing moisture sources, including condensation and leaks, as part of control. They nest in temporarily moist places outdoors, such as tufts of damp dead grass, and indoors they are often seen on sinks, counters and floors in kitchens and bathrooms. Fixing drips makes a home less suitable for them.
Do ghost ants smell like coconut?
When crushed, ghost ant workers give off an odour that UF compares to rotten coconuts. The related odorous house ant gives off a similar rotten smell, which Penn State describes as distinctive of that species. The smell confirms you have one of these Tapinoma ants; colour then separates them, since odorous house ants are uniformly brown to black.
Sources
- University of Florida IFAS, Featured Creatures EENY310 (IN532), Ghost Ant, Tapinoma melanocephalum (Nickerson, Bloomcamp and Pereira).
- University of Florida IFAS, Featured Creatures EENY290 (IN533), Pharaoh Ant, Monomorium pharaonis.
- Texas A&M AgriLife, Urban and Structural Entomology Program, Ghost Ant.
- Penn State Extension, Odorous House Ant.
- University of California Statewide IPM Program, Pest Notes: Ants, Publication 7411.
- Klotz, Oi, Vail and Williams, Laboratory evaluation of a boric acid liquid bait on colonies of Tapinoma melanocephalum, Argentine ants and Pharaoh ants, Journal of Economic Entomology 89(3): 673 to 677, 1996.
- Souza and colleagues, Urban ants as potential mechanical vectors of pathogenic and antibiotic-resistant bacteria in a Brazilian hospital, Medical and Veterinary Entomology, 2026.
- Rodovalho and colleagues, Urban ants and transportation of nosocomial bacteria, Neotropical Entomology, 2007.
- Lee and colleagues, Indoor occurrence of the ghost ant Tapinoma melanocephalum in urban homes in Korea, Korean Journal of Parasitology, 2017.
- The Pest Control Brief analysis of iNaturalist research-grade records, pulled October 2026.
