Top Photo: Asian needle ant (Brachyponera chinensis).
Depending upon who you reference, there are somewhere around 10,000 to 12,000 known species of ant in the world. New species are still being discovered. There’s an estimated total of some 20,000 species including what has yet to be described.
The number 1,000 is most often returned in searches for North American species. And it seems 192 species is the most recently calculated number for North Carolina.
I have no idea how many species reside here at the museum. More than likely, there are many more than the half dozen or so that I see regularly.
But it’s the Asian needle ant that’s come to the front lately. They tend to sting when disturbed, though in my experience with them, you have to disturb them quite a bit to get stung.
We used to have fire ants on campus, lots of fire ants. We’ve since eradicated them through diligent treatments around their subterranean nests. They were truly aggressive ants. Disturb one grain of dirt outside their mound and dozens, hundreds, even thousands of the little red devils would rush out of the nest looking for the person or creature who dare disturb them in their work. And, they’d make you pay for it with many bites, or rather stings. If you didn’t move out of range fast enough you’d be, first, wincing in pain, and then, itching for days, if not weeks.
Asian needle ants are not even close in their aggression towards intruders as are fire ants. You really have to make one angry to be stung, and they don’t gang up on you. The sting doesn’t seem as painful either, or as long lasting as fire ants. Though, if you react adversely to insect stings in general, it may be worse for you.
Asian needle ants tend to keep to themselves and avoid, rather than revel, in their aggressive interactions with humans. While picking up the ants in the vial in the photographs (by hand), I didn’t get stung once. I probably picked up a dozen ants and not one made an attempt to sting me. I don’t, though, recommend you picking them up.
I think most folks get stung when they feel an ant walking on them, go to brush it off or scratch in the area, and the ant reacts with a defensive bite and sting. Or an ant, or ants, gets trapped under clothing and stings when pressed between the clothes and the body.
Asian needle ants are obviously not native to North America. They were first encountered here in the 1930s but have only been recognized as a pest since the mid 00s, especially in the southeast.
They’re surprisingly easy to recognize once you know what to look for. They have a dark brown to black body with lighter brown or red-brown appendages, legs, antennae and mandibles. They measure about 5-6 mm long and have a long lean appearance enhanced by a long straight abdomen and a rather wide and straight thorax which is slightly more rotund anteriorly. Most ant species give the impression of having a big head, thin waist, and wide or bulbous abdomen, but these ants seem evenly proportioned throughout. You have to get close to see them but once you get the overall feel for their appearance, they’re hard to misidentify.
Another trait which can help in their identification is their inability to cling to or climb smooth surfaces. While most other ants can easily run up and down the side of a glass or window pane (or plastic vial as in the photo here) needle ants slip and slide and just can’t get a grip.
Asian needle ants seek termites as food but have been observed eating other invertebrates. And, they may be drawn in to sugar sources and other human food items (trash receptacles).
They can out-compete other species of ant or eat them directly. Taking out termites and other ant species may sound like a good thing but the native species play an important role in the natural landscape, among other things, wood decomposition and seed dispersal. These are things that go on largely unnoticed by most of us, but play a big part in what keeps the natural environment going.
Asian needle ants nest in small to large colonies numbering from the tens to thousands of individuals. They prefer to nest in damp areas like leaf litter, under rocks, rotting logs and may choose manmade objects as their base, like sprinkler systems and sidewalks.
They don’t necessarily form ant “highways” to and from a food source, but seem to forage in loose groups
If you want to control the ants, limit their numbers (you probably won’t eliminate them entirely), it’s suggested that you locate their foraging areas (anywhere you see more than just a few of the ants running around) and bait the area with protein-based insecticide baits. The ants bring the bait back to the nest, it’s consumed, and their numbers decrease.