Very small new generation of Crematogaster Scutellaris : why?

[Cylvouplay]

My Crematogaster scutellaris : there are new generations of VERY LITTLE sized minors. They are smaller than the first minors you get with a new queen. I don't know why. My guesses are :
- Not enough space : one of the growing room is very thin so they stop growing.
- Some diet change (too much/not enough sugar/protein?)
- Some disease?
- Reaction to predator (after some mass murder from an intrusion of predator lizard)
- Any kind of stress for the queen?
- Maybe they are normal sized speciallised ants I usually don't see because they usually stay deep inside the nest (I observed my ants are growing some mold of their own, I realised they did it on purpose when I used some UV light and saw them caring some mold to new areas, they love when I let old fruits in their space, as they implant the mold and when the old fruit is dry, they harvest the new mold, after sometime, I let them build like this a big mold of their own in a box,and I do observe that through the very little ones ants travel all the places, they are particularly specialised into mold cultivation, they are the only ants taking care of the big mold. And these small ants appeared only when the big mold was formed. So could be a link.

So what's the reason? I don't complain, the very little antlings are so cute ants but they are very sensible too, in the way if one is lost outside the nest for too long (few minutes) or I keep one in my hand and she is deeply frightened, she often experience nervous breakdown, unable to readapt to life after such a "choc", traumatised in fear and letting herself die in inaction. These ants are very cute but weak somehow. They act asif they knew they are weak/abnormal, lacking self-confidence, sometimes they fear the big ones which led in rare occasions, to be considered intrusions (and killed as such) and they tend to run for their life each time they travel an open space area... It's not "normal" but overall it's OK. I'm not complaining about it but I would like to know why.
Note : it's getting worse, they are getting smaller and smaller with new generations. But normal ants and even major are still coming too, it's not all the ants that are small.

[Camponotus]

Those are called nanitics (first generation of workers)

[ClashOwenBash]

Depends on the amount of protein the workers feed the larvae. So maybe increasing their protein intake will increase the general size of workers. But generally an ant colony would have slightly smaller workers even if that species isn't polymorphic. The smaller workers tend to stay in nest and look after the queen and brood. It isn't a problem but is interesting.

[Cylvouplay]

Depends on the amount of protein the workers feed the larvae. So maybe increasing their protein intake will increase the general size of workers. But generally an ant colony would have slightly smaller workers even if that species isn't polymorphic. The smaller workers tend to stay in nest and look after the queen and brood. It isn't a problem but is interesting.

Well there are two main strategies from ants about who are the ants going out, and scouting and harvesting water (going out for harvesting food is dangerous, guard rounds is more dangerous (specially for ants whose guards are going at dangerous places, it does happen with these Crematogaster, when many ants die, some ants will come and search for foes, and then stay here to protect others) ; going out for scouting is more dangerous because one can get lost or fall etc, and harvesting water (in the wild) is extremely dangerous for these species unable to swim or keep some air underwater. The "best" strategy I think is seen from species who chose to always have old ants doing the more dangerous things. Indeed the total loss of one ant dying is lower if the ant is old and close to die anyway. It's a huge saving of work for queen and feeding as it was to be replaced soon anyway... I've observed and I cannot tell if Crematogaster does it I would bet not.

Now if I have asked this question, it's because these small ants are MUCH MUCH smaller than anything I saw before from these species, and from this colony that is now several years old now. It's not just a normal variation, it's something like a third of the new ants that are very small, much smaller than anything ever seen by me (and these ants are common in my country) so that's why a reason should exist and I ask for help if anyone has ever heard about what could cause ants to be born abnormally small like that.

[Cylvouplay]

Those are called nanitics (first generation of workers)

It would be nice to read the question before giving some random answer... It's NOT a first generation, the colony is already a few years old. And I specified oin the very first line that these ants are much smaller than the nanitics of the first brood. Your help is appreciated (nanitics is the right word indeed and it help to have you reminding this as I made some Google search with this), but please, have a look at the real situation and question.

It's said that nanitics could happen in case of starvation, but this colony had access to plenty of food. It's possible that something in the organisation makes difficult for a part of the larvae/pupae to receive food? I searched for clues and opened some of the nurseries. One of them is appart and al ants inside are small and the height of the room is very little (the ceiling is very low one could say) maybe that cause less food to reach the place or maybe the size is limited by the space.

[ClashOwenBash]

Definitely interesting, I know their not reproductive ants but has your colony ever produced alates? I agree that the 'best' strategy is the older ants do more dangerous jobs, which is more visible in smaller colonies. Are you sure there the same species? I know it's a weird question but maybe they're different ants. Or have you seen these smaller ants doing the same jobs as the regular sized ones? Again I don't see it as a problem just very interesting.

[LasiusSapien]

off the top of my head but don't leaf cutter ants have super small minors in the nest for cultivating the fungus they eat perhaps it's similar with your ants too?

[Cylvouplay]

Indeed LasiusSapien, that's why I did open the question about the fungus (mold I called it as in the case of my Crematogaster, they do strangely keep seed of "mold" (or call it fungus) but they don't cultivate it at home but on rotting fruits around. It took time before I understood what they were doing, as it was in no way obvious, until with UV I was able to see that ants were carrying a fluorescent moisture-mold-fungus-thing COUNTER-direction of the nest (from nest to outside places) which was very strange behavior (I know the same could happen with the same ants and little baby aphid, which are fluorescent too by coincidence (or not) for "cultivation" too, or in the direction of garbage/graveyard, but here it wasn't) but the same fluorescence was there on the so-valued old fruits too. And I had observed earlier that these ants did prefer old dry mold fruits over juicy sweet fresh fruit which too was very bizarre. Only computing all these observations did I make the guess that they themselves selected what kind of mold/fungus is allowed on the new fruits and wait for this to develop then it explain why the once dry and full of fungus fruits were more valued. It's not proven but it's the only explanation that makes sense by now. It wouldn't surprise me if for instance, they did such cultivation to produce some specific antibiotic or such ant medicine (as there seems not to be anything really nutritive on this old dry fruits but who knows).
Because I don't see these fungus inside the nests (there are 4 main nests, it's standard for crematogaster to have many) I think it's still pretty different. But because of these observations, I would advise anyone keeping crematogaster, to give the ants some fruits and NOT change these when they become dry, so that the ants can cultivate these things,as maybe it could halp them fight some diseases or who know what else so important to them they make all these efforts for it.
=> So if anyone knows about leaf cutter ants it could of some help (even if no certainty can be concluded) about the existence or not of smaller ants to take care of the fungus (?).

*** SPAM ***, indeed I checked the ants, they are definitively the very same, only they are just smaller than any of this species I saw earlier, even in the same colony (which is some years old already) - because it's a semi wild ant keeping, it could very well have been colonised by some other species indeed, but really I assure you it's verily the same. Only smaller. Yes they had alates, they do have alates right now hiding deeply in the nest, I caught a few males already, seen a queen I guess, not 100% sure. They all do jobs 100% interchangeable, but I tend to observe that small ants do prefer to do what other small do. In a few situations, I felt the small ones can sometimes be afraid of the big ones (but that is in their first days out I think). An additional reason why I imagine the situation is abnormal. But you know,it's difficult when you talk about feeling, it's not scientific observation anymore. Not sure. What is more certain, is that the nanitics ants di fear more life in general,so they are seen more at less dangerous places. Like protected places where lizard never been seen; Still they do travel places where lizards are in ambush so they are killed too...
The phenomenon did increase and increase (more and more little ants, and little ants more and more small-sized). And now it's going back to normal, slowly. (The rate of ants population turn-over is much higher in my colony because this semi-wild configuration makes the ants statistically short-lived alas. Mainly because of lizards I don't know how to get rid of, who are eating my ants with malice, in ambush close to their path but places where I can't see them. So the high turn-over makes it pretty fast to see population change. In one hand the colony is very very productive and grows fast to some point, in the other hand, once reaching some size, it becomes easy food for lizards and it becomes painful).

[Cylvouplay]

Again I don't see it as a problem just very interesting.

Yes indeed, and I would like to know in order to be able to reproduce it at will in the future if possible without hurting the girls.
My favourite theory right know is the lack of protein. Not that there was not enough in the harvest area, but because I gave too much easy sugar and for some time they were found of this grenadine syrup. Later some bees attacked my ants. Not killing them, but annoying them and stealing the honey. I killed a dozen of the bees until they stopped harrassing here, and the ants took the bees (so protein) back to nest for pupaes, that was I think, the beginning of the slow "way back to normal". But still it may change again very fast. Nothing's certain.

I started today to serve grenadine syrup mixed with Whey protein. If that ends the nanitics phenomenon, it may be a clue for the protein theory. And then I may check lowering the protein again to see if it could be done again... ? Isn't it how science goes?

[Cylvouplay]

"off the top of my head" ==> first time I meet this idiomatic formulation. I like this It would be "au pied levé" in french. "Là comme ça au pied levé" is the expression most often for us. Don't ask me why : it's far from obvious to me, but well in use.