Daniel Kronauer

With about 100 species, the spiny ants of the genus Polyrhachis form the most diverse group of ants on Borneo. Here are two beautiful examples, the golden P. bihamata (look at those fishing hooks!) and the especially armed P. armata. Danum Valley, Sabah.

Removing the cover reveals the ants’ brood, in this case several pupae. There were no queens in this nest, and I assume it was a satellite nest of a larger colony.
Danum Valley, Sabah, Borneo

It’s the abode of spiny ants (Polyrhachis mucronata or related species). These ants build their nests by combining silk from their larvae with plant debris.

What’s this piece of art on the underside of a leaf you may ask?

‘Insane’ images depict ant species in stunning 3D New method for visualizing organisms opens the door for mass digitization efforts

I talked with Warren Cornwall about this work for Science: www.science.org/content/arti...

And here’s more coverage in the NYT, including some beautiful animations: www.nytimes.com/2026/03/05/s...

Antscan

Thanks to micro-CT and www.antscan.info, you can now explore high resolution, 3D ant images from anywhere in the world. Fantastic work from Julian Katzke, Francisco Hita Garcia, @economo.bsky.social, Thomas van de Kamp and colleagues just dropped: www.nature.com/articles/s41...

But it doesn’t have the cute sawfly larva eyes, which threw me off…

I don’t. First I thought sawfly, but somehow doesn’t look right. Any suggestions?

While photographing the zombie ants at Danum Valley, I noticed this funky larva chomping on and ultimately devouring the entire fungus stalk growing out of the ant’s head. I knew that Ophiocordyceps fungi have been used in traditional medicine for centuries. Turns out other animals consume them too.

Amazing photo! 🤓🐜🪲

Ophiocordyceps infections result in local “graveyards” of zombified ants, often on the underside of leaves in the low vegetation. The ant I posted yesterday actually shared its leaf with another zombie. Here’s the full scene.

Ophiocordyceps zombie fungi infect ants and manipulate their behavior. The ants climb up vegetation, anchor themselves by biting into a leaf, and die. Out of their head then grows a fungus stalk that releases spores into the environment. And so the cycle continues. Danum Valley, Sabah.

Another picture of Diacamma, this time a worker at the nest entrance. Somehow this species seemed to construct unreasonably large entrance funnels (see how small the ant is in comparison). Danum Valley, Sabah.

A Diacamma ant foraging on a leaf in Danum Valley, Sabah. These ponerines are sometimes called fingerprint ants. You’ll see why if you zoom in and look at the cuticular sculpturing on the thorax and gaster.

The workers of the giant forest ant (Dinomyrmex gigas) are polymorphic, i.e., they come in two sizes and shapes: The minors (first two pictures) and the majors (last two pictures). Both are huge though - minors just over two centimeters and majors up to three centimeters in body length.

Portrait of a giant forest ant (Dinomyrmex gigas). What an absolute puppy! 🐜 🐶 🐜 Danum Valley, Sabah.

Stictoponera menadensis are not particularly small ants. However, they are completely dwarfed by their neighbors, the giant forest ants (Dinomyrmex gigas), whose large workers measure almost 3 cm in body size. Here, the two are foraging next to each other on a buttress root in Danum Valley, Sabah.

A Stictoponera menadensis (subfamily Ectatomminae) worker foraging in the leaf litter at Danum Valley, Sabah, plus another specimen on white background.

Colonies of this species often lack queens. Instead, unlike in most ants, workers can mate and take over egg laying as so-called “gamergates”.

Great to know that someone is bringing some order to this! 🙏👍 🐜

There’s pre and post molecular phylogenetics. DNA sequence data completely changed how we think about ant evolutionary relationships over the past 23 years or so.

Feel free to shoot me an email.

Nice, thanks @formicula.bsky.social! I found the situation w D. thoracicus confusing and wasn’t sure what’s what. Are you working on the group?

New York City snow day weather update @rockefeller.edu. It’s purty! ❄️ ⛄️

Portraits of the Dolichoderus colony members inhabiting the epiphytic myrmecophyte (ant plant) in Danum Valley, Borneo:
A queen, a worker, and a male.

My best photographs of 2025, a short thread.

A tobacco hornworm on one of its favorite foods, a garden tomato plant (Texas, May 2025). This one makes the cut because it is more aesthetically pleasing than I was aiming for, somehow.

Beautiful!🤩

A section through the tuber reveals the galleries inhabited by the ants. This is where they keep their brood, along with several winged males. In one of the chambers, I also found two dealate, mature queens (I’ll post portraits of the individual colony members separately).

The species kinda keys out to Dolichoderus thoracicus, the cocoa black ant. However, that species seems to be a “bucket taxon” containing several distinct species. Your normal D. thoracicus are black and nest in the soil. Clearly, this is something different.

This miniature world, a part of an epiphytic plant, was inhabited by a species of aggressive Dolichoderus ant. The ants were guarding and entering/exiting various entrances into the inside of the tuber.

After a night of heavy rains at Danum Valley, I found this alien meteorite that had fallen onto a trail.