Swarming ants can be an intriguing natural phenomenon to observe, even if it might feel a bit unsettling at times. You may have seen these ants forming groups, seemingly working together in unison to accomplish a common goal. The coordinated movement is fascinating, and understanding the reasons for their swarming behavior can shed light on the complex lives of these tiny creatures.
There are several factors that can lead to ant swarming, including mating season and environmental changes. In some cases, ants swarm to find a suitable place to establish new colonies. Should you come across a swarm of ants, don’t worry; they typically disperse within a day or two, moving on to their next destination. By learning more about the swarming behavior of ants, you’ll develop a newfound appreciation for the sophisticated social structure that powers these little insects.
Species and Castes
There are over 12,000 known species of ants, including carpenter ants and black ants. Within each species, ants are divided into different castes, which include workers, soldiers, and reproductives. Workers are typically wingless, while the reproductives, such as queens and males, have wings. For example, in a carpenter ant colony, you may find:
- Workers: Wingless, responsible for foraging and caring for the colony
- Soldiers: Protecting the colony
- Reproductives: Queens and males with wings
Anatomy of Ants
Ants have unique anatomical features that distinguish them from other insects. Some key traits include:
- Antennae: Ants have two antennae, which are bent or “elbowed.”
- Wings: Reproductive ants have two sets of wings, with the front wings being longer than the hind wings.
- Waist: Ants have a distinct, pinched waist, also known as the petiole.
- Color: Varies among species but can range from blackish-brown to black.
Here is a comparison table for the anatomy of ants vs. termites:
|Antennae||Bent or “elbowed”||Straight|
|Wings||Two sets, unequal length||Two sets, equal length|
|Waist||Pinched or “wasp-waist”||Straight|
|Color||Blackish-brown to black||Pale, translucent|
Role in Ecosystem
Ants play a crucial role in maintaining the balance of ecosystems. They contribute to nutrient recycling by decomposing organic material, aid in soil aeration, and help control other insect populations. For example, some ant species are predators of insects that may damage crops, making the presence of ants beneficial to farmers.
In some cases, ants also serve as a food source for other species like birds and reptiles. In ecosystems where ants consume large quantities of cellulose, such as carpenter ants, their waste contributes to nutrient cycling and promoting plant growth.
Remember, ants are an important part of our ecosystems, and understanding their species, anatomy, and roles can help us appreciate their presence.
Formation and Structure
Ant colonies begin with the founding stage, when winged queen and male ants fly out of mature colonies to mate. After mating, the queens lay eggs, from which the first worker ants will be born. The queens do the work in the early stages, but once worker ants are there, they take care of the tasks within the colony.
Ant colonies often have a caste system, with winged reproductive ants, wingless worker ants, and sometimes multiple queens. The structures of ant colonies can vary, with some species building nests in soil or wood, while others construct elaborate nests inside buildings.
Dynamics Within a Colony
In ant colonies, the worker ants are primarily responsible for maintaining the colony, and they display incredible collective intelligence. These workers communicate using chemical signals, and according to Stanford University biologist Deborah Gordon, their communication can orchestrate complex tasks, allowing the colony to thrive as a superorganism.
Different tasks performed by ants within the colony include:
- Collecting food
- Defending the nest
- Taking care of the brood (eggs, larvae, pupae)
As your knowledge of ant colonies grows, you’ll find the ways in which these insects work together to be truly fascinating.
Understanding Swarming Behavior
Swarming is a behavior observed in ants, primarily during their mating process. Ants, like other social insects, exhibit a fascinating trait called swarm intelligence, allowing them to work together and make decisions as a group. As a result, they can efficiently find food sources and protect their colonies.
During the swarming period, you might notice a large group of winged ants called swarmers. These are the reproductive members of the colony, and they take part in the nuptial flight, a process where winged ants mate in the air.
Some characteristics of swarming ants include:
- Winged reproductive ants leaving the colony
- Mating during the nuptial flight
- Swarm intelligence guiding group behavior
Swarming Season: When and Why
The swarming season typically occurs in early spring to late summer, depending on the ant species and geographical location. In some regions, rainfall can also trigger swarming activity. The exact timing of swarming varies based on temperature, humidity, and other environmental factors, like food availability.
Swarming behavior is an essential part of the ant life cycle because it enables the ants to mate and spread their genes to new territories. After mating, the female ants lose their wings, become queens, and establish new colonies. The males die shortly after the nuptial flight.
To summarize, swarming in ants:
- Occurs in early spring to late summer
- Depends on temperature, humidity, and environmental factors
- Helps ants mate and spread their genes to new territories
Now that you understand the basics of swarming ants, you are better prepared to recognize and appreciate this intriguing natural phenomenon.
Recognizing Ant Infestation
Swarming ants can be a sign of an infestation. If you notice discarded wings around your home or ants in large numbers, this could be an indication of an infestation. Another sign is the presence of mud tubes on the exterior of your walls or foundation. These tubes act as tunnels for ants to travel in and out of your home.
Ants are attracted to moist environments, so be attentive to any areas with excess moisture in your space, such as damaged wood or mulch. They may also be seen near cracks around windows or doors, seeking food sources in your kitchen or commercial buildings.
Locations Prone to Infestation
Some areas are more susceptible to ant infestations, like the North Central United States, where specific ant species are prevalent. In general, places prone to infestation include:
- Foundations: Make sure to regularly inspect your home’s foundation for cracks that can offer ants an entry point.
- Wood: Damaged or moist wood, such as trim or structural beams, can attract ants and provide them with a food source.
- Soil: Ants can create nests or find shelter in the soil surrounding your home, particularly conditions are damp.
- Exterior: Cracks in windows, doors, or walls can serve as entry points for ants seeking food and shelter.
To prevent infestations, try to reduce moisture-related issues in your home, seal cracks in the foundation or exterior, and keep food and trash properly contained. Remember, a proactive approach is the key to protecting your home from ant infestations.
Ants Versus Termites
Differences and Similarities
While both ants and termites are social insects that live in colonies, there are a few key differences between them. For example, ants have elbowed antennae, while termites have straight, beadlike antennae. Moreover, ants’ front wings are larger than their hind wings, while termites’ wings are all of equal length. Notably, there are also similarities between these insects, like their social structures and colony dynamics.
You may come across various ant and termite species. Carpenter ants, for instance, can cause significant damage to wooden structures, similar to how subterranean termites and drywood termites can lead to infestation issues.
Swarming Termites: An Overview
Swarming ants and termites are the winged reproductive members of their respective colonies. Termite swarmers are typically associated with termite season, a time when mature colonies release their winged reproductives in search of a mate and a suitable location to establish a new colony. As a homeowner, spotting termite swarmers may be a sign of an active infestation nearby.
Subterranean termites are typically the most dangerous, as they build their colonies in the soil and can be harder to detect. Termite treatments are often required to resolve these infestations.
Here’s a comparison table of some key differences between ants and termites:
|Antennae||Elbowed and bent||Straight and beadlike|
|Wings||Front wings larger than hind||All wings of equal length|
|Infestation||Less damaging to structures||Can cause severe damage|
In conclusion, knowing the differences between ants and termites can help you identify and address potential infestations in your home. Be cautious and seek professional assistance if necessary.
Addressing Ant Infestation
There are several methods you can use to tackle an ant infestation on your own. One of the first steps you could take is to vacuum any visible ants, their trails, and their entry points into your home. This helps remove the ants as well as their scent trails, making it harder for them to find their way back.
Another option is to use natural or store-bought ant repellents. Examples include:
- Diatomaceous earth
- Vinegar and water solution
- Essential oils like peppermint or eucalyptus
Remember to apply these repellents near entry points or along ant trails to prevent them from entering your home.
When to Call a Professional
In some cases, DIY solutions may not be enough to address a severe infestation. Here are some signs that it’s time to call a professional:
- Large and persistent ant colonies
- Structural damage to your home
- Difficulty locating the ant nest
Professional entomologists and pest control experts are equipped to locate and eliminate ant nests more effectively than a typical homeowner. They can perform a thorough inspection of your home, identify the type of ants causing the infestation, and recommend the best course of action, such as targeted termite treatment.
In summary, addressing ant infestations depends on the severity of the issue and your level of comfort in handling it yourself. Either try DIY solutions or consider contacting a professional for help.
Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.
Letter 1 – Swarming Texas Leaf Cutter Ants
Subject: What Is This Insect?
May 11, 2013 7:46 am
We first noticed these bugs yesterday. They were all over the ground in little holes. Some of them have wings and some are wingless. There were hundreds of them. I have searched the internet and cannot find anything that resembles this insect. Is it an ant or wasp? I was wondering if this insect stings or bites. Thank you so much!!
These are Texas Leaf Cutter Ants, Atta texana, or some other Leafcutting Ant in the genus Atta. You are witnessing the swarming activity. The winged ants are alates, the sexually reproductive queens and kings that will fly off and mate so they can begin a new colony. The individuals without wings are the nonreproductive workers. Leafcutting ants are eaten in Mexico where they are considered a delicacy. According to BugGuide: “In Texas these ants damage weeds, grasses, plum and peach trees, blackberry bushes and many other fruit, nut and ornamental plants as well as several cereal and forage crops. The ants do not eat the leaf fragments they collect, but take them into their underground nest where they use the material to raise a fungus garden. As the fungus grows, certain parts of it are eaten by the ants and fed to the larvae. This fungus is their only known source of food. Leaf cutting ants will attack pine trees but ordinarily they do little damage when other green plants are available. During the winter when green plant material is scarce, seedling pines are frequently damaged in parts of east Texas and west central Louisiana. Where ants are abundant, it is almost impossible to establish natural pine reproduction. In such sites, young pine seedlings often are destroyed within a few days unless the ants are controlled before planting.”
Letter 2 – Swarming Citronella Ants
Location: North New Jersey
October 10, 2011 8:49 am
Hi. I found these bugs pouring out of a hole in my backyard. There are at least two types. I think they are both ants, but could also be termites. (My next step is to see if I need to treat my house.) Thanks in advance.
This is a beautiful photo, but we haven’t the necessary skills to identify the ant species. Your photo contains both the winged reproductive alates and workers of the same species. They are not carpenter ants, so we don’t believe it is necessary to treat your house.
Thank you for the reply. I also sent the picture to Viking Pest Control who said they appear to be citronella ants, a “nuisance” and treatment not necessary unless inside the house. Whew!
Hi again Jim,
There are many questions about Citronella Ants on BugGuide, and all those appear to be in the genus Lasius and subgenus Acanthomyops. The common name refers to the smell the ants give off when smashed. The yellow color is also indicative of the genus Lasius according to BugGuide. Thanks for writing back with that information.
Letter 3 – Swarming Ant Mystery
Subject: Is this an ant war? I’ve never seen one before…
Location: Meadowview, VA, USA
August 25, 2014 6:26 am
I took my son to school this a.m. and in the 10 minutes it took me to go and come back, this swarm of wingless ants appeared on the edge of my driveway (it was not there when we left). There are several “puddles” of ants along the edge of the driveway where it meets the lawn, with trails of ants moving between them like little rivers. Up close there appears to be one on one fighting, with the big puddles being the “winners?” swarming around on top of immobile “losers?”… on the edges of the “puddles” there are individual ants wandering around, but other than size (a few are much smaller than the others, but all of them are fairly small ants) they appear really similar to me– I can’t see an obvious two species fighting. Is this maybe that situation caused by wasp secretions, where they fight themselves? Or is it two or more colonies duking it out? I’ve sent several pictures from my phone– I hope at leas t one of them is good enough quality for you to identify world war 3 for me!! Thanks for your awesome site– I love to visit and learn new stuff!
Signature: Jeri Ward
I wasn’t sure which pix would be clearest, so I’m sending the rest in hopes at least one will be good enough to id.
We are posting the clearest of the eight images you submitted. Alas, we are not very good at Ant identification and we believe even an ant expert might have problems with an exact identification, but we have some thoughts. Since these are small ants, two species that come to mind are both nonnative, invasive species, the Argentine Ant (which is reported on BugGuide from nearby North Carolina and Tennessee) and the Red Imported Fire Ants, which according to BugGuide: “The Red Imported Fire Ant is the most aggressive and widespread of the fire ants found in North America. It was introduced from South America into the United States between 1933 and 1945. If their nest is stepped on, the workers rush out and sting the feet and legs of the intruder. Each sting results in a small, acutely painful wound that develops into a pustule in 24 to 48 hours. As the pustules heal they become itchy and can become infected. ” Of the Argentine Ant, BugGuide states: “Thought to have first arrived in the United States in coffee shipments in New Orleans around 1891. A major pest in United States for several reasons: able to nest in diverse habitats, produces great numbers of individuals due to many reproductive queens in a colony, eats large variety of food (omnivorous diet), coexists amiably with other colonies of same species, exterminates competing native species of ants wherever they occur, and invades homes in large numbers in search of food and water. When established in an area, the number of individuals is mind boggling, with large files of workers running up and down trees, on fences, on the ground, and everywhere else; considered one of the most persistant and troublesome of house-infesting ants.” We believe this is either linked to swarming activity and the emergence of winged alates, or perhaps something else caused a colony to come above ground, like perhaps flooding. Did you water the lawn earlier? We apologize for not being much help.
Letter 4 – More Swarming Citronella Ants, we believe
Are these Lasius Flavus?
Location: Ottawa, Ontario, Canada
October 11, 2011 1:27 am
My wife noticed these ants flying around (not particularly well) in our basement. We pulled stuff away from the hole that’d been cut in the wall some time previously for access to find these ant coming out from under the pavement around these pipes. The photos were taken Oct 10, 2011. It was fairly cold but then record warm on the weekend, I wonder whether that has something to do with their emergence? We think tree roots are coming up under the house, we believe that we can actually see some around the pipe, would that be why they ended up where they were? The ones with wings were about 1cm in length and had an abdomen the same colour as the ones without wings.
We just posted a photo that we believe to be swarming Citronella Ants and they look very much like your ants. When ants swarm, they will often do so over a great portion of their range simultaneously, which lends credence to the possibility that you also have Citronella Ants. From our brief research, Citronella Ants are in the genus Lasius and the subgenus Acanthomyops according to BugGuide. According to BugGuide, Lasius flavus is in the subgenus Cautolasius. We don’t feel comfortable taking this to the species level, but we do believe the genus is correct. Perhaps someone with more knowledge on Ants can clarify the identification.
Letter 5 – Swarming Ants
Subject: Termite or ant?
June 6, 2014 4:25 pm
Literally out of nowhere (I didn’t see them an hour ago), we have hundreds of these. This is only about 1/3 of them. Just as quickly as they came, they went back under the wood porch. Termite or ant?! 🙁 randomally there are also a few red fire ants mixed in without wings.
These are swarming Ants, and the winged individuals are alates, unmated reproductive individuals that will fly off, mate and begin new colonies.
Letter 6 – Swarming Ants
Subject: Is it a wasp??
Location: central Iowa
October 8, 2014 4:25 pm
These bugs are in our garage. They seem to be falling from the roof. About a month ago this happened and they reappeared today. The swarm appeared quickly and once I opened the door they flew out eventually. They look like flies but not quite. We have had a wasp nest it that area in the past. If you can figure something out that would be great! I looked it up and found a cicada killer that looked similar. Thank you!
Mistaking for wasps these flying Ants, which are members of the reproductive caste known as Alates, is understandable since Ants and Wasps are both classified in the order Hymenoptera. Since you had two swarms appear in your garage, we deduce there is at least one colony living within the footprint of the garage.
Letter 7 – Swarming Red Imported Fire Ants
Subject: Driveway Swarm of these Flying Insects
Location: Southern California
May 4, 2017 8:58 pm
This morning there were hundreds of these flying insects lying dead in the driveway, grouped in a fairly small area about 6 feet across. I scooped up a few onto white paper, added a ruler and took a picture. I’m curious – are these flying ants or are they (heaven forbid) termites?
These are the reproductive alates of the only species of Ant ubiquitous across Southern California, the Argentine Ant. When it is time to swarm, winged males and females take flight to mate and start new colonies. In our opinion, the Argentine Ant is the most destructive invasive exotic species in Southern California, and it does much more damage than the dreaded Med Fly.
Correction: May 14, 2017
We just received a correction from Ben that these are more likely Red Imported Fire Ant alates, and this BugGuide image does support that correction. According to BugGuide: “native to South America, adventive in our area and spreading throughout so. US north to MD-IL-MO-TX-CA); introduced to many Old World countries” and “The most aggressive and widespread of the fire ants found in North America. It was introduced into the US from Brazil between 1933 and 1945. If their nest is stepped on, the workers rush out and sting the feet and legs of the intruder. Each sting results in a small, painful wound that develops into a pustule in 24-48 hours. As the pustules heal they become itchy and can become infected.”
Letter 8 – Swarming California Harvester Ants
Subject: California Harvester Ants
Location: Red Car Property, Silver Lake, Los Angeles
June 23, 2014 1:57 am
I might of happened across some future queens leaving the nest of one of the Harvester Ant colonies on the north end of the Red Car Property in Silver Lake (Los Angeles).
The winged ants were 3 times larger than the small ants ushering them out of the nest. The workers using the main entrance fall somewhere between these two in size.
Unfortunately, while attempting to get a better shot, I cast a shadow over this entrance. The small ants quickly ushered the winged ants back into the nest, while others came out to defend against intruders. Mostly they just ran around posturing, and checking the perimeter, then returned to the nest
I was looking for references to Harvester Ants & was surprised (although I shouldn’t be) that they’ve disappeared from your neighborhood. We’ve got several thriving colonies on the north end of the Red Car Property. The colonies on the vacant lots on my part of the neighborhood have disappeared as the vacant Hillside lots have either been built or used for parking in the past 10 years.
As always, thanks!
Signature: Diane E
We are positively thrilled to get this marvelous addition to our site, especially since it sheds a bit of light on our failure to follow through with a posting we wanted to make regarding a Mount Washington sighting. When we moved to Mount Washington in the mid 90s, we would often see California Harvester Ants in the street outside our house as well as on the nearby south facing hillside. Then we moved to another nearby location in 2000, and we stopped seeing the California Harvester Ants, instead being plagued by the invasive Argentine Ants. Local entomologist Julian Donahue cannot recall ever seeing California Harvester Ants in Mount Washington, so while walking to a friend’s house the second week in June when we espied a lone Harvester Ant on the sunny south facing slope near our old home, we decided we needed to return with a camera to document the sighting. Alas, time ran out and it did not get it done, but it is still on the back burner. Your submission has inspired our crack photographic staff to to head out later today to try to find some worker Harvester Ants in our own neighborhood. We are happy to hear they are also thriving in nearby Silverlake.
Glad to help out – I had no idea you hadn’t seen them in so long. But it makes sense with all the development over there. I used to see a lot more 20 years ago all over my hood…
Letter 9 – Swarming Cornfield Ants
Subject: Invasion of Orange Ants
Location: Young’s Point Ontario N. of Peterborough Ontario
September 4, 2012 3:40 pm
Sept 1 2012, Young’s Point Ont. N. of Peterborough Ont. I beleive a member has recently posted the same insect This happens each year to the date. Weather is always humid with the grass cool and not in sun light. It will last all day into evening. It seems a mass of these ants coming up from the ground. There is also what I will call Gnats, I am not sure if I am correct on this but many of them. They inter-act with the ants. This area is around our septic system. Our grounds are mostly rock and half clay to sandy earth. We have had little rain as with most folks. It is just amazing to see as I said you can put your time to this happening.
Signature: Donna Lynn
Since posting the photo that your first commented upon, we have learned that these are swarming Cornfield Ants or Citronella Ants in the genus Lasius. The Cornfield Ants are sexually dimorphic with males being black and females red. The winged ants are the Alates or reproductive males and females. A mated female will become the queen of a new colony. The red ants without the wings are the sterile female workers. The seasonal appearance makes sense for a mature colony that will produce new Alates each year and they will swarm when weather conditions are right.
Letter 10 – Swarming Edible Leafcutter Ant
Subject: BIG flying ants
Location: Atenas, Costa Rica
May 16, 2012 5:07 pm
These big critters swarmed our open-air ”ranchito” last night. Their bodies are 25mm +/-. Four wings of translucent amber with two main veins on the main wing. Abdomen and thorax are globular, dark brown with a slight ”velvety” look. Abdomen is smooth to the anterior and then terminates in segmented area to posterior. Relatively small head, compared to the other body sections. Prominent pincers. Bent antennae.
Signature: Newtonian in Atenas
Your swarming monarch is a reproductive Leafcutter Ant and they are considered delicacies in Mexico and parts of Central and South America. After mating, a queen will set up a new colony.
Letter 11 – Unusual Ant Swarm
Subject: ALL THE SAME ANT IN THIS SWARM?
Location: Tonasket, WA
July 24, 2012 10:45 pm
They seem to be coming or going under the sidewalk… 3 kinds. Big red w/wings, skinny black w/wings and short fat red w/no wings. They are not flying, it’s about 1 hour from dark and they don’t look like they’re mating or eating. What else is there to do?!?
The winged members of this swarm are reproductive Alates that will eventually take wing, mate and set up new colonies, however, you photograph brings up more questions than we have answers for. We imagine that the nuptial flight was soon to begin unless some other reason caused this group of ants to surface, like a flooded colony, though none appear to be carrying eggs, larvae or pupae which is what they would normally do if they had to flee suddenly. The other thing that is unusual that you have mentioned is the black and red winged individuals in the same swarm. Perhaps you have an ant species with sexual dimorphism, but we are not aware of a species with such distinct differences between the sexes. Some ants raid other colonies and make slaves of other species, but the slaves would not be mating individuals and only fertile kings and queens have wings. We found a nice online article called Social Parasitism in Ants that describes that phenomenon. Perhaps we will be able to find an answer in the future or perhaps one of our readers will be able to come to our assistance in this matter.
No, I didn’t! Pretty sure it is sexual dimorphism in this case, the alate males being black, the new queens red….but there are colonies that get enslaved by other ants that might result in something like this, too. Try contacting Alex Wild, he would be able to tell you more…. Oh, looks like a colony of “citronella ants,” genus Lasius, and orange-ish rather than red for the worker caste.
Ed. Note: We did find an image on BugGuide showing the color variation and sexual dimorphism in swarming Citronella or Cornfield Ants in the genus Lasius.