Argentine Ant vs Longhorn Crazy Ant
Argentine Ants and longhorn crazy ants are easy to mix up at a glance, but a few details separate them quickly. Here is how to tell which one you found and what, if anything, you should do about it.
Quick answer
Check for this first. An Argentine ant has uniform light-brown body with one flat node, while a longhorn crazy ant has long legs and antennae relative to its body.
Side-by-side comparison
| Argentine Ant | Longhorn Crazy Ant | |
|---|---|---|
| Group | Ants | Ants |
| Scientific name | Linepithema humile | Paratrechina longicornis |
| Size | 2–3 mm | 2.3–3 mm |
| Colors | Brown | Black and Gray |
| Legs | 6 legs | 6 legs |
| Wings | No | No |
| Bites or stings | No | No |
| Risk | Nuisance | Nuisance |
| Key feature | Uniform light-brown body with one flat node | Long legs and antennae relative to its body |
Key differences
- Color: Argentine Ants are brown; longhorn crazy ants are black and gray.
- Where found: look for Argentine ants in the kitchen and in gardens and on plants; longhorn crazy ants turn up in the kitchen and in lawns and grass.
- Signature feature: Argentine Ants: uniform light-brown body with one flat node. Longhorn Crazy Ants: long legs and antennae relative to its body.
How to identify Argentine ants
A small, light-to-dark brown ant that forms huge, cooperating supercolonies. Wide, busy trails often stream into kitchens during hot or rainy weather.
- Uniform light-brown body with one flat node
- Very wide, steady trails several ants across
- Musty, greasy odor when crushed
How to identify longhorn crazy ants
A dark, slender ant with extremely long legs and antennae that runs in fast, jerky, seemingly random paths. It nests in soil, trash and wall voids, mostly in warm southern states.
- Long legs and antennae relative to its body
- Erratic, zigzag running instead of straight trails
- Grayish sheen from fine body hairs
Which one is more dangerous?
Neither is more dangerous than the other; both are rated nuisance on our scale.
Argentine ants don't sting and rarely bite; they protect aphids and scale insects on garden plants. Crazy ants rarely bite and don't sting; their sheer numbers make them a nuisance.
Where and when you'll see each
Argentine Ants turn up in the kitchen and in gardens and on plants, mostly in spring, summer and fall. Longhorn Crazy Ants turn up in the kitchen and in lawns and grass, mostly in spring, summer and fall.
Because they share habitat, you may find both in the same place, so check each individual.
What to do if you find one
Argentine Ants: Apply sugar-water baits outdoors along trails. Read the full removal guide for more.
Longhorn Crazy Ants: Use sweet and protein baits in rotation. Read the full removal guide for more.
Biology: ants
Ants live in colonies ruled by one or more egg-laying queens. The workers you see are sterile females foraging for the rest of the colony, so killing visible ants rarely solves anything. Winged ants, called swarmers, appear when a mature colony sends out new kings and queens.
Frequently asked questions
What is the main difference between Argentine ants and longhorn crazy ants?
Color: Argentine Ants are brown; longhorn crazy ants are black and gray.
Which is bigger, an Argentine ant or a longhorn crazy ant?
Argentine Ant: 2–3 mm. Longhorn Crazy Ant: 2.3–3 mm.
Do Argentine ants or longhorn crazy ants bite?
Argentine Ants do not bite. Longhorn Crazy Ants do not bite.
Where are they usually found?
Argentine Ants: in the kitchen and in gardens and on plants. Longhorn Crazy Ants: in the kitchen and in lawns and grass.