13 replies to this topic

[dspdrew]

I've seen a video of Tetramorium running in circles on a sidewalk once if I remember right, but just the other day found one of my Acromyrmex versicolor colonies doing this in their out world. I thought it was interesting, but didn't get any video of it. Since I felt like they weren't getting anything done (when they really needed to because I'm trying to move them into a new nest) so I stirred the substrate up a bit, and they stopped.

 

Now just today I came home and found my colony of Pogonomyrmex rugosus doing the same thing. These run a lot faster, so it really caught my eye. They seemed to be running around the perimeter of where the light was shining on the ground in the out world. I tried turning on some other lights to get a better video, and I noticed they started to scatter and run around more chaotically. I quickly turned the other lights back off, and they quickly reformed their circle. Now in the video you can see what I'm talking about. As soon as I turn off the light they scatter in every direction, and as soon as I turn the light back on they immediately form right back into their circle.

 

I don't know what they think they are accomplishing, but I think this just further proves how stupid Myrmicinae seem to be. Has anyone ever seen Formicinae do this?

 

[Crystals]

How old is this colony?

I seem to recall someone mentioning that Pogonomyrmex could be tricked into triggering a mating flight by getting a certain temperature.  I think you may have hit that temperature.  I bet if you had alates and no lid they would be all over. 

Did you just add that light?.  Perhaps  the light is triggering a guard reaction.

[dspdrew]

Oh yeah that could be mating flight behavior. Retroman is the one who breeds Pogonomyrmex in captivity.

[dspdrew]

So today I purposely left the light off, and when I got home they were wandering around slowly in no pattern at all. I turned the light on, and it's been a few hours now, and none of them are running around the light. They're still just wandering around slowly and aimlessly. Pretty strange.

[drtrmiller]

They are walking "in circles" because the bulb is very close to the nest and focused at a single point in the middle—a "hot spot."

 

Whether this is a reaction to the heat or the light makes no difference—if the light source was further away such that it did not create a hot spot in the middle, you would not observe the behavior.

[dspdrew]

That doesn't explain why they do it when the light is on all day and not when the light is turned on later in the day. It only takes probably three minutes or so, to get up to temperature.

[dspdrew]

BTW, I left the light on all day today, and none of them are running around in circles.

[drtrmiller]

A negative after several positives doesn't necessarily prove anything.

 

You can modify the environment to isolate the potential cause by averaging the response over a number of days or instances.

• Close proximity light without heat (LED)
• Close proximity heat without light (ceramic)
• Change position of light/heat source to eliminate or accentuate hot spot
• Et cetera

Edited by drtrmiller, October 29 2015 - 7:02 PM.

[Subverted]

Maybe it has something to do with polarization of the light, don't some ants use that for finding their way?

[dspdrew]

 

A negative after several positives doesn't necessarily prove anything.

 

You can modify the environment to isolate the potential cause by averaging the response over a number of days or instances.

• Close proximity light without heat (LED)
• Close proximity heat without light (ceramic)
• Change position of light/heat source to eliminate or accentuate hot spot
• Et cetera

 

 

I wasn't trying to prove anything, because I didn't make any claims. You were the one that made a claim, and the negative (two actually) disproved it. I was just pointing that out.

[drtrmiller]

Your video proved that the change in environment was affecting behavior.  The tests I suggested were merely to isolate the variable in the environment to determine the root cause of the behavior.

 

"I left the light on all day today, and none of them are running around in circles" could very well be a false negative, signs of acclimation or conditioning, or the previous instances could have been an anomaly.

 

Either way, you obviously did create the topic to inquire as to why the ants were behaving this way—and completing a few different tests would easily provide more insight into a possible answer to the question.

[dspdrew]

They're running in circles again today. I wasn't all that interested in getting to the bottom of this, considering how much stuff I have going on right now, but now I kind of am. Here's what I will do, since this is not much work at all. I'm going to replace the light with an LED bulb that's pretty close to the same brightness. That will have almost no heat at all coming off of it, and will rule out heat as a factor. It was really kind of already ruled out though for the fact that when I turned other lights on, they started to scatter.

[dspdrew]

So I put the incandescent bulb over my Acromyrmex colony and now they started circling haha.

 

[BrittonLS]

I wonder if your ants use the sun to orient themselves at all. I know some do. If so, it could be a similar behavior to moths around a light. The ants are trying to go in a straight line in relation to the sun, which to us looks like them running in circles.