International Rock Flipping Day: The Ants

Did you know that today is International Rock Flipping Day?

The idea is to go outside, flip over a few rocks, and record what you see. The resulting posts will be published at Wanderin’ Weeta.

After looking under a couple of rocks, I posted about most of the creatures I discovered (including a very cool case-bearing larvae) at Growing With Science. Of course flipping rocks is a fabulous way to find ants (and “experience” ants in other ways, too), so let’s take a look at what ants were hiding under rocks today.

The area I chose has mowed grass with a brick edging around it, as well as some rocks piled up in a drainage ditch. It isn’t uncommon to see Forelius running along the edging, so it was no surprise to find a few under the rocks as well.

Southern fire ants were in full force, too.

I was surprised how much more red these show that the ones in my yard a football field-length away.

I managed to get stung while taking this photograph. (Flipping rocks does has its hazards.)

Of course, Dolichoderinae don’t sting.

But they are more than willing to bite.

At least it was sitting still, so it is in focus 🙂

Did you participate in International Rock Flipping Day? What did you find?

Forelius mccooki ants

We have some amazing ants in Arizona.

People always comment on the tiny ants that run rapidly along sidewalks in great numbers.

Here’s a very amateur video in real time, to give you an idea of their speed at about 90 degrees F. I particularly enjoy the traffic noises in the second part. I thought the revving sounds were quite appropriate. 🙂

Based on their behavior, I figured they were genus Forelius.


These particular ants are apparently Forelius mcccooki rather than the common Forelius pruinosus, based on the hairs on their antennal scapes, etc. Dale Ward has a page about Forelius pruinosus in Phoenix. Alex Wild has photographs of F. mccooki.


The fast little ants stretched the limits of my photography skills.

forelius -2


Here I tried the doubler.


One thing I noticed while watching is that the F. mccooki workers seem to have greater than usual amount of color variation.

For most ants, if you open a colony you will see lighter than usual individuals. These are the newly emerged callows. Their color will darken over time. Generally the callows work inside the nest.

Seeing the mix of light and dark colors in the foragers is less common. Alex Wild has a photograph of color variation in Forelius pruinosus workers.

What’s going on? First of all, Forelius exoskeletons are easy to see through, as Dale Ward shows.

Secondly, the colonies have multiple queens and could be genetically diverse.

I have another idea, but without a lab or lab equipment, I’ll have to wait on that one.

Continuing Toothbrush Experiment:

What I can test is whether Forelius ants are attracted to a toothbrush. When I put the toothbrush into a foraging trail, no response.


I’ll keep carrying the toothbrush.