Results tagged “frass”

What does ant dung look like? Cristina


I came across your interesting website and I wanted to find out if there are any images available for what ant dung looks like.

Many thanks,


Hi Cristina,

Thanks for your question! I have to admit, although I've spent a fair amount of time looking at ants, they're usually either dead or foraging: I've never caught one in the act, so this was a fun question for me to try to answer. Luckily, I have access to some other people with lots of ant experience, so I'm able to share their insights.

First, though, let's start with some terminology. When insects eliminate undigested waste, it's called "frass." This is a general term, that also (depending on who you ask) encompases other little particles and exudates that result from insect activities. For example, wood dust that results from carpenter ants gnawing through wood is sometimes considered "frass," even though the carpenter ants don't actually eat the wood - they just cut through it. Since your question is obviously directed towards elimination, we'll focus there.

Something about ants that many people don't realize is that as adults, they are unable to consume big chunks of food. Their jaws are often good at holding and/or cutting through objects, but not well-adapted for chewing food into pieces small enough to swallow. Some ants can eat pollen grains, but solids much bigger than that will not pass through the narrow constrictions at an ant's neck and waist. In a peculiar reversal of the "mamma bird" situation we've all seen on nature shows (and in real life, if you're lucky), adult ants must bring solid foods back to the nest, where the ant babies (larvae) eat it, and then vomit some of the chewed and partially digested food back into the mouths of the adults.

Because adult ants never eat solid foods, their frass tends to be a dark-colored liquid--at least as far as the ants that AntAsk Team members Corrie, James, and Steffi are familiar with are concerned. They (the ants, not the people) also excrete metabolic waste, analogous to urine, in the form of white urate crystals, which James describes as mixing together with the feces in various proportions: "sort of like coffee creamer."

The ant larvae, however, are a different story. They only eliminate waste once during their development, in the form of a dark, compacted mass (can I say "turd" on this blog?) shortly before pupation. This cuts down on diaper changes considerably. Interestingly, albeit disgustingly, sometimes adult ants eat this meconium (reported in Cerapachys biroi by Ravary and Jaisson 2002, and Cephalotes rohweri by Creighton and Nutting 1965). I apologize if you're reading this right before a meal.

As I wrap up this post, I realize I haven't actually pointed you in the direction of any real pictures. There are some pictures of meconia among Alex Wild's excellently curated collection of ant pictures, but I'm not aware of any pictures of an adult ant in the act of defecating. Refuse piles in subterranean ant nests, and below arboreal ant nests are more commonly photographed, but they often contain the bodies of dead workers and discarded prey parts, in addition to frass in the strict sense. So the best I can do is leave you with James' vivid image of a fine white powder mixing into a dark drop of liquid, like creamer into coffee. If I find a good picture of an ant in the act of "frass-ing", I'll let you know!

Hope this helps!
Jesse Czekanski-Moir & the AntAsk Team

ps. if you're interested in other things that come out of ants, please see this previous post about ant pee:

On the chemistry of ant excreta

Dear AntBlog:

I am Eva Rogge, R&D Engineer at Europlasma, located in Belgium, Europe. We are specialized in nanocoatings, for example to provide water repellent and oil repellent properties to a material. Our coatings can be applied on all kinds of materials: textiles, plastics, electronics.

I have been contacted by a person who makes electronic apparatus used outdoors. He has noticed that ants are attracted by the electromagnetic fields. They come into the apparatus, live there, and produce excreta. Because of these excreta, short circuiting of the devices occur.

The idea is now to apply a nanocoating on these electronic components to protect them against the excreta of ants. To investigate if this is achievable, I was wondering if you have any idea of the main components of the feces of ants.

Kind Regards, Eva

Dear Eva:

Ant "feces" is not feces in the same sense as for us mammals. The diet of adult ants is mainly liquid, containing only the tiniest solid particles, so there is only a small component of indigestible solids. Further, the insect equivalent of kidneys, called Malpighian tubules, empty into the rectum rather than into a separate bladder as in our species, so the nitrogenous waste or urine, in the form of uric acid crystals suspended in a fluid that is mainly water, is mixed with the feces. This results in a light brown (café au lait color, if you will), thick suspension of mixed waste, excreted as droplets through the cloaca (anus) at the tip of the ant's abdomen. In sum, I would say that the general description of the ant excreta is a suspension composed primarily of uric acid crystals and very small particles of insoluble carbohydrates (cellulose, chitin) and cuticular (exoskeleton) proteins in a polar liquid.

In nature, ants typically use latrine areas for the deposition of this waste, apart from where they feed and rest and rear their brood. An internet search will reveal that there is a fair bit of literature on ants infesting electrical circuitry, but this is mostly unsatisfying, in that the studies do not really elucidate either why the ants accumulate on electrical circuitry, or why they soil the premises while there.

Finally, I would suggest that it would be good for you to team up with an analytical chemist, so that more precise details of the chemistry of ant excreta could be determined.

James C. Trager & the Ask Ant Team

I'm not an ant observer, but I recently noticed ants on my sidewalk behaving in a manner I hadn't seen before.

The sidewalk is shaded by an oak tree that is dropping thousands of tiny, hard cone-like kernels about 1/8" long and slightly less in diameter. Simultaneously this tree also drops mature acorns, so I don't know whether the tiny cones are related to the acorn process or not. The ants are also very small - 1/8" or less long.

About a week ago, I noticed occasional tightly gathered 'circles' of cones - usually about 1-1/2" to 2" in diameter, and about one to three or four cones in height. Upon further examination we discovered the circles were being 'built' by the ants, and also discovered that these 'circles' were being built around dead or dying caterpillars. Some ants were continuing to build the pile - while a steady stream of others were going back and forth - presumably carrying bits of the caterpillar back to the nest. After the ants abandon the pile, there is nothing left of the caterpillar.

I suspect this is not an unusual ant activity, but since I know little about ant behavior, I'm curious about the reason for the temporary burial of the caterpillar. Are they hiding or protecting their food-source from other predators - restricting the movement of a still living caterpillar - or what?

Here are a couple of photos - the first showing the cones as they distribute when they fall, and the second shows a caterpillar in the process of being surrounded and covered.

Thanks for your help.

Dave Owen
Lakeland, FL


Dear Dave,

As you live in Florida, we reached out to a Florida ant expert, Lloyd Davis, and here is what he had to say:

"About this ant behavior: First, the "cones" are caterpillar dung. I suspect from the color of the ants on the caterpillar that the ants are imported fire ants. I have seen fire ants bring dirt onto a glue trap to gain access to food trapped in the glue. This however looks too far fetched. Unless someone watched the process and saw the ants positioning the caterpillar dung, I suspect some other reason for their arrangement and that it is just a coincidence that the ants are feeding on the caterpillar in the middle of the pile."

In the insect world, we often call insect "dung" or waste by the name frass. This may explain why the frass is accumulating near the caterpillar as this is the source.

Red imported fire ants (Solenopsis invicta) are unfortunately common in Florida. You can see photos of them here and here.

To learn more about red imported fire ants you can read some of our previous posts including here and here.

Thank you for contacting AntBlog,
Corrie Moreau & the AntAsk Team


Hi Corrie -

Thank you for pursuing an answer to my 'ant' question and notifying me of Mr. Davis on-line response; however I'm still puzzled by a number of points that likely have been explained had I been more thorough in my question.

If the 'cones' are, as Mr. Davis says, caterpillar frass, I am astounded by the quantity, distribution, size and shape uniformity (they look very much like sub-miniature pine cones or a tiny shelled ear of corn). When I spoke of 'thousands' of the little 'cones', it was not an exaggeration. Although no longer happening, when it was the entire portion of the sidewalk beneath the oak tree (roughly 160 sf) would be littered with these 'cones' within 24 hours after the sidewalk was swept. Incidentally, the appearance of the 'cones' started about two weeks before I wrote, and stopped almost totally and suddenly a few days after my previous note. Except when there was a 'circle', the distribution of the cones was almost uniform over the entire sidewalk area beneath the tree - and oddly there never any on the sidewalk beyond the foliage of the oak tree.

I should have noted that I did personally see the ants constructing these 'circles', and there was always a dead caterpillar or other insect in the middle. It was amusing to see these tiny ants (perhaps 1/16" in length is more accurate than 'smaller than 1/8"') swinging the 'larger-than-themselves' cones to and fro as they carried them to the pile. As the 'cone-circles' grew, the cones around the pile almost totally disappeared, defining an increasingly larger 'empty' circle largely devoid of cones (the 'cleared' circles got as large as 6" in diameter from the pile center).

I'm very familiar with imported 'fire ants', and the 'circle-builders' may well be that type, although they seem smaller and darker in color than the many other colonies we constantly battle on our large lot. These ants are almost black in color - with just a hint of red, and both front and back seem to be rounded - rather than 'wasp-shaped'. The fire ants we have in our yard all have piles of excavated sand around them that continue to grow until we poison them. The small ants about which I wrote seem to live beneath the sidewalk, and I've not seen any excavated dirt or sand, although I know it must be there.

Neither my sister nor I have ever noticed this phenomenon before in the many years we have lived here. If it does happen again, I'll try to get more information and a close-up photo of an ant moving one of the cones.

Again, I want to thank you and Mr. Davis for responding to my inquiry.


Regarding your second inquiry, here is what another ant expert, James Trager, had to say:

"I agree that the "cones" are caterpillar frass, and from their size, would even go as far as to suggest that they were produced by some sort of oak-feeding saturniid. Leaves are not an especially nutritious food, especially tannin-filled oak foliage, so caterpillars have to eat prodigious amounts to fuel their rapid growth rates, from tiny egg to several-inch long caterpillar in just a couple of weeks or so. This explains the rapid appearance and disappearance of the frass, and why all the frass was under the drip-line of the tree. .

Fire ants almost invariably bury large items for butchering. It doesn't surprise me that, in the absence of convenient soil particle, sawdust, or what-have-you, the ants used caterpillar frass for their burying ritual. The smaller, darker description of the ants also fits for a "butchering party" of fire ants. These gatherings usually comprise mostly or only the smaller workers, which are more uniformly dark colored."

I hope this helps!

All the best,
Corrie Moreau, James Trager, & the AntAsk Team



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