Let's talk about Ants (The Animal)

[fiksal]

I have a couple questions then


Is it true that ants have a sort of a social order? Where workers assigned jobs?


I also often see very large ants roaming around. Are they same species and colony as tiny ones? What is their purpose?


What are all winged ants? Are they females? Is there purpose to find another colony?



When I was little I saw an aftermath of a dramatic event in our garden. On one side lived a colony of small slightly reddish ants, on another, 20? meters away, brown/black ants. One day I saw piles of bodies by the brown colony, of both kinds. I was imagining that red ones went to fight brown ones. In the aftermath the brown ones were collecting bodies of their own and didn't immediately touch red ones. I would imagine they would have still taken and eat them, or not? I wonder what they did with their own.
Some details I can maybe be mistaken on.

[Alan Phipps]

The larger ants are probably the soldier caste that protect the smaller worker caste from various attackers. They may have enhanced mandibles compared to general workers. Alternatively they could be formative alates (see below).

Flying ants are alates, sexually mature females and males. After mating (the swarming increases success rates) the larger females (potential queens) chew off their wings, and the males, job done, just die.

It is possible that the probably stronger formic acid concentrations in the smaller red ants made their bodies less attractive for recycling compared to those of the larger black ants. Alternatively, it may be that the black ants detected an infection or infestation in the the other nest's ants. Ants do not usually eat their dead, although they can, but the gathering and disposal habit may reduce the risk of nest infection or may just be ingrained foraging behaviour.

[fiksal]

The larger ants are probably the soldier caste that protect the smaller worker caste from various attackers. They may have enhanced mandibles compared to general workers. Alternatively they could be formative alates (see below).

I see! If they are soldier ants then I am curious why there are so few of them. Or is that all that's needed?

Flying ants are alates, sexually mature females and males. After mating (the swarming increases success rates) the larger females (potential queens) chew off their wings, and the males, job done, just die.

So the wings are just for mating?
And what's the point of multiple females in the colony then - I thought only 1 queen is laying eggs?

It is possible that the probably stronger formic acid concentrations in the smaller red ants made their bodies less attractive for recycling compared to those of the larger black ants. Alternatively, it may be that the black ants detected an infection or infestation in the the other nest's ants. Ants do not usually eat their dead, although they can, but the gathering and disposal habit may reduce the risk of nest infection or may just be ingrained foraging behaviour.

Ah interesting. What does "recycling" mean for the ants?

[Alan Phipps]

Ant colonies may have specialised undertakers for the task. They usually carry their dead to a sort of graveyard or take them to a dedicated tomb within the nest. Some ants bury their dead.

On soldier caste ants (if that is what they were), I suspect the rule is threat-based. In the UK we don't frequently have termites invading ant territory, or vice versa. The ratio of soldiers to workers is set by the queen in her secretions. Obviously the more unproductive soldiers you have, the more workers you would need to replace and support them, but having too few soldiers poses increased risk of invasion. Soldiers usually patrol entrances and nest chokepoints and key essentials, hence they can be deployed in far fewer numbers.

More queens equals more potential new nests.

[BaronVerde]

Quite a few anthropocentrisms in here

Evolution is a complicated thing, and an organism's ability to fill a niche depends on all of its aspects, not just a single or a group of traits. Many aspects and the pressure they exert aren't directly visible or obvious, like genetic variety/variability, competition, presuure from environment, climate, etc. What we see of a species or any such classifaction unit is a snapshot of an ongoing evolutionary process. A lot of modifications were sorted out as not being helpful in the current niche.

It is best not to try to find a purpose in an organism, there is no such thing in biological evolution, it is physics after all. But some functional aspects or morphology may in combination lead to a slight advantage in the current niche, to pass on the genes to the next generation. It is difficult to find out which ones are important to achieve that, and which ones are just carried along, momentarily, or because they where useful in the past, are rudiments or whatever.

[fiksal]

Ant colonies may have specialised undertakers for the task. They usually carry their dead to a sort of graveyard or take them to a dedicated tomb within the nest. Some ants bury their dead.

On soldier caste ants (if that is what they were), I suspect the rule is threat-based. In the UK we don't frequently have termites invading ant territory, or vice versa. The ratio of soldiers to workers is set by the queen in her secretions. Obviously the more unproductive soldiers you have, the more workers you would need to replace and support them, but having too few soldiers poses increased risk of invasion. Soldiers usually patrol entrances and nest chokepoints and key essentials, hence they can be deployed in far fewer numbers.

More queens equals more potential new nests.

The way you describe them does make me think those are soldier ants then. Unfortunately I am unable easily to find any photos that can demonstrate what ants I mean. (though googling "brown worker ant vs soldier ant" looks similar to what I am asking about)
I used to see them a lot in Russia, but in North America ants are a bit different. I've seen less of such size variation.


A little more about wings then. Do I understand it right, that winged females leave the original colony? Do winged males as well?

Another occurrence that was quite common in Siberia, is seeing hundreds of winged ants, moving about, in addition to much increased activity around ant hills. That event lasted only a couple days I think. Maybe that was a yearly thing. Enough to be even a bit of nuisance when working at our garden.
So what is happening there?

It is best not to try to find a purpose in an organism,

if you mean my questions about wings, then the question about purpose was more like - how are ants using them.

speaking of evolution, the genes for having wings were carried out by more successful organisms, so they are either useful or they are piggy backing on another useful trait

[Alan Phipps]

The winged males fly, mate (or not) and then soon die. They don't return or move on.

The flying swarms are the mating frenzy triggered by environmental conditions when the time is right. If there are winged but walking swarms then they are probably either waiting for wings to stiffen up from fluid insertion before flight, or exhausted participants that are about to either lose their wings or die. A scattered swarm could be due to weather conditions or it could more likely be to introduce genetic variation from different same species nests into the mix. (Like nests will usually swarm at the same time.) Also the new queens may scatter before landing to found their new nests.

[BaronVerde]

... how are ants using them ...

I am not an ant-ist , just general paleontology.

I hate to speculate, but as I understand it and I don't pretend to be right:
- not all ants have wings
- only fertile drones and the queen fly
- it seems to me as if those who develop them do so seasonally as a swarm, as part of their procreation cycle
- a swarm (group/herd/flock/etc. of similar individuals) offers protection against predators (a general concept)

It might be worth researching if there is a reason that part of the procreation cycle for those ant-species takes place outside of the nest, triggering the swarm. One can probably find work on that subject.

Edit: partly ninja'd

[fiksal]

@BaronVerde , gotcha

The winged males fly, mate (or not) and then soon die. They don't return or move on.

The flying swarms are the mating frenzy triggered by environmental conditions when the time is right. If there are winged but walking swarms then they are probably either waiting for wings to stiffen up from fluid insertion before flight, or exhausted participants that are about to either lose their wings or die. A scattered swarm could be due to weather conditions or it could more likely be to introduce genetic variation from different same species nests into the mix. (Like nests will usually swarm at the same time.) Also the new queens may scatter before landing to found their new nests.

Alright, interesting, so to bring this full circle. Is each winged female a start of a potentially new colony then? Surely no existing colony would want them, right?

[clakclak]

Ant colonies may have specialised undertakers for the task. They usually carry their dead to a sort of graveyard or take them to a dedicated tomb within the nest. Some ants bury their dead.

On soldier caste ants (if that is what they were), I suspect the rule is threat-based. In the UK we don't frequently have termites invading ant territory, or vice versa. The ratio of soldiers to workers is set by the queen in her secretions. Obviously the more unproductive soldiers you have, the more workers you would need to replace and support them, but having too few soldiers poses increased risk of invasion. Soldiers usually patrol entrances and nest chokepoints and key essentials, hence they can be deployed in far fewer numbers.[...]

Important to note here is that not all ants have soldier casts. In fact there is a difference between polymorphism and a dedicated soldier cast. In Europe the vast majority of ants (and by that I mean almost every species) do NOT have "real" soldier casts. Some ants like ants of the genus componotus are polymorphic though, that means they come in different sizes and can also differ in looks depending on the size. Here is for example a picture of Componotus Nicobarensis (an Asian species). These ants differ greatly in size but the bigger ones are not actually soldiers.


Also termites do not pray on ants, which is something I am sure Alen Phipps knows, but I found it came across a bit unclear. Termites eat dead plants. In ant termite relations ants are the predators.

[Alan Phipps]

No, they have to start afresh elsewhere. The semen stored in them from mating in the swarming with many different males usually from different nests will last her the rest of her productive life which can be up to 15 years of egg-laying with no further fertilisation!

The male ants come from unfertilised eggs, while the queen determines in advance whether a fertilised egg will be a worker or a potential queen.

[mrbadger]

I read a paper some time back that said most of the world is essentially owned by one colony of black ants. they spread widely and this why that particular species don't attack each other, they're all related. they can be found on almost all continents now. I don't know all the details because it's about 20 years since I read that paper.

[clakclak]

I read a paper some time back that said most of the world is essentially owned by one colony of black ants. they spread widely and this why that particular species don't attack each other, they're all related. they can be found on almost all continents now. I don't know all the details because it's about 20 years since I read that paper.

The species is called Linepithema humile (I was under the assumption that they were called Idomyrmex Humilis, but that seems to be outdate), their trivial name is Argentine ant. Kurzgesagt did a nice video on them. This video by Ants Australia goes into more details.


The reason they do not attack each other outside of their native range, as explained in the Kurzgesagt video, is that due to the emigration process the genetic diversity within the invasive populations was lowered. Normally most ants attack any other ant colonies they find, even if they are the same species (though there are exceptions).

[mrbadger]

There's a video now? Nice. I only ever knew about it from the paper I read, and i only read that due to my panic studying before I started my degree.

[clakclak]

@BaronVerde , gotcha

The winged males fly, mate (or not) and then soon die. They don't return or move on.

The flying swarms are the mating frenzy triggered by environmental conditions when the time is right. If there are winged but walking swarms then they are probably either waiting for wings to stiffen up from fluid insertion before flight, or exhausted participants that are about to either lose their wings or die. A scattered swarm could be due to weather conditions or it could more likely be to introduce genetic variation from different same species nests into the mix. (Like nests will usually swarm at the same time.) Also the new queens may scatter before landing to found their new nests.

Alright, interesting, so to bring this full circle. Is each winged female a start of a potentially new colony then? Surely no existing colony would want them, right?

While many ant species only tolerate one queen per nest, there are others in which multiple queens start a new nest and even other that accept new queens into allready existing colonies. There are also ant species without queens. Instead each ant in these species has the potential to lay eggs, but only one dominant female called the gamergate does. She stops others from laying eggs by destroying parts of their body responsible for reproduction right after birth. Some species also have a mix of Gamergates and traditional queens.