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?
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.
(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.)