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Dear Ant Consult-Ant

I have an ant question!

Subject: Ant activity

In mid May at about 6:00 in the evening in Ann Arbor, Michigan, USA, I was walking along the sidewalk and saw some small black ants swarming. I like to watch queens come out so I sat down to watch. I stayed about 45 minutes and I didn't see a single wing. What I did see was amazing. The ants were small black ants. After a few minutes the ants started forming patterns. Two ants that were narrower than most would lock jaws. Then two normal ants would grab onto the heads of these two to form a plus sign or X. They would stay like that for 6-7 minutes then breakup. Sometimes 4 more of the normal ants would grab onto the abdomens of the 4 ants and form a plus sign of eight ants. In the time I was there there were always 15 to 30 of these symbols. I am not sure how many separate nests were participating. I left to get a camera and a collecting jar. When I came back the show was over. Is this common behavior? I have not seen it before. What was going on?

Dear Dave,

Clusters of ants acting in an excited manner do often indicate swarming. As you noticed, however, you would expect to see winged queens and males mingled among the workers. Instead, from what you describe, it sounds like you witnessed a a fight between two nearby colonies of ants.

When ants fight each other, they tend to latch onto antennae and legs and pull hard, thus creating the X's you describe.

Above three ants from one colony pull on a single ant from another colony.

More ants join in, and it becomes a tug of war.

Sometimes one species of ant attacks another, such as these weaver ants attacking a much smaller species.

(Photo from Wikimedia) This one looks more like a Y than a X.

They may use the same behavior with prey.

(Photo from Wikimedia)

Ants may fight other ants to gain access to food, to defend their nest from hostile take over, or to defend the area around their nest (territory).

Some ants are more likely to fight than others. In Mark Moffett's Book Adventures Among Ants, he has a chapter devoted to the territorial disputes between two huge colonies of Argentine ants in California. Along the front line literally millions of ants die every month in what is a never-ending struggle.

On the other hand, a dispute between honeypot ants may be resolved by mere posturing, no actual fighting may occur.

Sounds like you witnessed an interesting event, which left an impression on you. Without knowing the species involved, etc., I hesitate to speculate further as what was happening.

Thank you for sharing this question. Let me know if you make any more interesting observations.

-The Consult-Ant

(Note: As I mentioned previously, I have been the “Consult-Ant” on the Leaping from the Box website. I answer questions about ants and ant farms. From now on I will post the answers here, and when Karen has time she will also post the answers on her site.)

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13)  If a colony with only one queen ant were to die, would she be replaced with another? Or does the colony die out. If she gets replaced, then are there always alates available to replace her at any time? Or are they only produced prior for the mating season, nuptial flight, and etc.? Is there any way of the colony knowing that the queen is about to expire, like some kind of special pheromone?

Mike, you've taken us on quite an adventure with your questions. It's been a fun learning experience for me to dig up the answers for the ones I didn't know about. If you have any more questions, or you'd like clarification about anything, feel free to ask.

As for the ability of ant colonies to replace their queens, this is a topic that comes up often.

For many temperate ant species with a single queen, the answer is that once the queen dies, the colony is a goner. The worker ants will not accept one of their sisters as a new queen, workers can not become a new queen themselves, nor can they raise a new queen like honey bees do. Some worker ants can produce eggs once the queen has died, but those eggs are unfertilized and will become males.

That said, there are a number of ant species that don't fit the norm. In species like the Argentine ant, Linepithema humile, colonies have many queens, and the males and queens mate right inside the nest. Having many queens allows the colonies to become large quickly. In fact, one problem with Argentine ants is that when they are introduced to places they have never been before, they form such large colonies that they can quickly overwhelm or drive out many native ants, even ants much bigger than themselves. Argentine ants proved to be hugely successful at spreading and are now found almost worldwide.

Another strategy is found in the ponerines that don't have a distinct, physically different queen. In those species, the egg-laying individual is called a gamergate. When one gamergate dies, the next high-ranking worker takes over laying eggs. Hoelldobler and Wilson discuss this in detail in their book, Superorganism.

Most ants colonies have distinct periods or seasons when the reproductives are produced, but that will vary from species to species and even somewhat from year to year, due to differences in environmental triggers, amount of food, age of the queen, etc.

Finally, the queen probably won't give off a specific signal that she is weak (it wouldn't be to her benefit), but there might be a decrease in the pheromone(s) she produces to attract the workers and keep them from producing eggs.

By the way, you might be interested to know that researchers recently synthesized the pheromone of the queen black garden ant and were able to show that it does suppress the ovaries and egg-laying ability of worker ants. See:  University of Copenhagen (2010, July 14). Elusive ant queen pheromone tracked down. ScienceDaily. Retrieved July 24, 2010, from http://www.sciencedaily.com­ /releases/2010/06/100630101016.htm

For more information on ant queens, see a previous post answering questions about ant queen development.

If anyone has more information about this they'd like to share, please let us know.

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Mike wrote to the "Consult-Ant" with a number of questions about ants. I am going to try to answer each one in a separate post. For the original list of questions and links to all answers, visit here.

11)  Are there some ant species that simply drink water and then other species that absorb it from the humidity of the air? Or do they all do both?

Your question reminded me of the movie Microcosmos, which contains some great footage of ants and other insects dealing with water. I'll throw the trailer below.

The second thing I thought of was communal peeing as a flood defense, where ants drink water and then run outside to "pee," removing excess water from their nests. You know you want to click the link and see it, so go ahead. I'll wait for you to come back.

Ants need water. Many drink water from drops and small puddles.

ants-drink-honey
Ants drinking honey

Ants can obtain moisture from a variety of sources, including food. Leafcutter ants and weaver ants obtain moisture from plant sap. Many ants tend aphids and other insects of the order Homoptera for liquid honeydew, which is full of water. Other ants visit extrafloral nectaries on plants for a source of sweet liquid.

Ants have also been shown to use "tools" to help them collect larger amounts of water and sweet liquids than they could carry in their crops. Harvester ants (Pogonomyrmex) have been known to toss sand into liquid food and then carry it back to their nest. Aphaenogaster ants use bits of plant material as sponges to soak up liquids and transport it.

Mark Moffett found Diacamma ants decorate their nests with feathers, which collect dew in the early morning. (I have seen Forelius ants carrying feathers here in Arizona.) He also suggests that the dead ants spread around the nest might also serve for dew collection.

As far as "absorbing humidity," Coenen-staß (1986) suggested that the red wood ant, Formica polyctena, might be able to absorb water vapor based on sorption rates. Other scientists have investigated desiccation resistance, and suggest that, for example,  some ants can reclaim their internal water through structures called "rectal pads"(Hood and Tschinkel, 1990).

Videos showing ants drinking water:

Pay close attention to the rear section (metasoma or gaster). Look how it swells and becomes clear as the ant drinks.

Microcosmos trailer. For a review, see my Growing With Science blog.

The bottom line is that worker ants do drink water, and give it to other members of the colony. As for humidity absorption, that is relatively unknown.

For more information:

Coenen-staß, D. (1986). Investigations on the water balance in the red wood ant, Formica polyctena (Hymenoptera, formicidae): Workers, their larvae and pupae. Comparative Biochemistry and Physiology Part A: Physiology. 83 (1): 141-147.

Hood, G. and W.R. Tschinkel. (1990). Desiccation resistance in arboreal and terrestrial ants. Physiological Entomology, 15 (1):  23-35.

Moffett, M.W. 2010. Adventures Among Ants: A Global Safari with a Cast of Trillions. University of California Press, Berkeley.

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I have an ant question!

I have an ant farm with Little Black ants but not a queen. can one of the ants become a queen?

Thanx
Zarah

Zarah,

I'm afraid once an ant becomes an adult ant, it can no longer change form or shape. It can't shed its skin or grow.

Adult worker black ants can not become queens, and the worker ants can not lay eggs that will become queens either.

There are a few types of ants where special workers become "queens," but those ants are much more like wasps, and you wouldn't want to keep them in a regular ant farm. If you'd like a more detailed explanation, check the ant queen development post.

How are your little black ants doing? I hope they are doing well.