Screen Shot Saturday - Shapes and Sizes of the Wood Ant

MikeSlugDisco

Community Manager
Staff member
Community Manager
This week's Screen Shot Saturday showcases Formica rufa, the wood ant.

Formica rufa (wood ant) colonies can consist of tens of thousands of workers which can be a range of sizes. In Empires of the Undergrowth you will be able to build your wood ants with a variety of roles.

The largest with the dark heads are melee soldiers; the smallest will perform jobs around the nest.

Between are the acid sprayers: they'll shoot a stream of debilitating formic acid at intruders to the nest.

FormicaRufa-20.5.17.png
 

Serafine

Queen
Backer
Beta Tester
Ecosystem Beta Tester
Re: Screen Shot Saturday - Castes of the Wood Ant

Formica rufa does not have castes.

They are NOT polymorphic in the way Camponotus
CamSansabaenus1-S.jpg

or Pheidole
cfjelskii4-S.jpg

are.

They just have workers of different sizes, like all ants do.
All Formica rufa workers have the same color pattern (unlike Camponotus where the amount, intensity and pattern of secondary colors like red can vary wildly between members of the same colony).


Also the size of an ant doesn't really have something do do with it's aggressiveness and fighting abilities. Leafcutter major workers (the ones that cut leaves, not the soldiers) are huge but bad at fighting and there are super small ants like Strumigenys which are hyperaggressive tiny packages of terror that can fend off ants of more than fifty times their own size.


Btw Formica rufa queens are a socioparasitic and cannot found colonies on their own, they need to infiltrate colonies of other Formica species (like Formica fusca) and murder their queen (or return to their original colony, Formica rufa colonies can have several dozen queens).

Would be cool if there was a level where you play as a Formica rufa queen and have to invade an enemy nest (evading guard posts and be a bit stealthy) to kill the queen and then all the workers defect to your side and you can start using them to kickstart your own colony.
 

JohnSlugDisco

Administrator
Staff member
Developer of EotU
Re: Screen Shot Saturday - The Wood Ant

Of course you are correct and Formica rufa are only Queens and workers, apologies for the mistake. I have corrected the post accordingly.
 

MikeSlugDisco

Community Manager
Staff member
Community Manager
Re: Screen Shot Saturday - The Wood Ant

It's me who's responsible for posting Screenshot Saturdays, so my mistake. I'd offer my head in shame but I'm also aware the Formica rufa queen doesn't demand summary executions, at least not in nature.
 

Serafine

Queen
Backer
Beta Tester
Ecosystem Beta Tester
FeaReaper_06 said:
Wait is this a thing we can do for other types of ants or is this just for the wood ants.
Well, technically there shouldn't be any different types of Formica rufa workers except different sizes (all of them can spray formic acid, even the smallest) but I guess having a single worker type that is a good melee fighter AND has a ranged attack might be a bit much, so I can see why they split that into different unit types for the game.

Carebara diversa (asian marauder ants) could be pretty cool to play because they really have these swarms of tiny 2-3mm minors, some rare medium workers (about 9-10cm) and some massive huge Supermajors (15-18mm).
And unlike Camponotus which have a rather fluid caste system with all shapes and sizes between the smallest and the largest present, Carebara really only come in these three sizes with nothing in between (some rare exceptions might exist in a colony though).
Pheidole species also have something similar.
 

Liam

Administrator
Staff member
Developer of EotU
Serafine - We concede that separating ranged and melee rufa soldiers is more of a gameplay decision than based on reality. However, I was wondering if you could clarify some points about polymorphic ants, as you seem to know your stuff.

Currently we get most of our info from Wikipedia (if it has an entry for the ant we are interested in), but it can often be vague, antwiki.org is good too. Though, when cross-referencing with other sources of information I will often come across information gaps or contradictions.

The Wikipedia entry for Formica rufa states that they are polymorphic and "measuring 4.5–9 mm in length" with a reference. You state that they are "not polymorphic" and yet you also say that they can come in different sizes. If there are distinct different sizes in a single colony, is this not evidence of polymorphism (using the following definition)?
Polymorphism - "A discontinuous genetic variation divides the individuals of a population into two or more sharply distinct forms". Does polymorphism imply castes or can these things be independent in some way?

The way that rufa queens found new nests is really interesting, we will have to add a disclaimer into the in-game wiki to point out that our rufa nests shouldn't really have self founded.
 

Serafine

Queen
Backer
Beta Tester
Ecosystem Beta Tester
Liam said:
Serafine - We concede that separating ranged and melee rufa soldiers is more of a gameplay decision than based on reality.
Yep, that makes sense.

Liam said:
The Wikipedia entry for Formica rufa states that they are polymorphic and "measuring 4.5–9 mm in length" with a reference. You state that they are "not polymorphic" and yet you also say that they can come in different sizes. If there are distinct different sizes in a single colony, is this not evidence of polymorphism (using the following definition)?
Polymorphism - "A discontinuous genetic variation divides the individuals of a population into two or more sharply distinct forms". Does polymorphism imply castes or can these things be independent in some way?
Basically the workers of every ant species (with some rare exceptions like Myrmica bull ants and some ponerine species) come in different sizes.

However the term polymorphic is usually only used when they differ not just in size, but also in shape (morphology). The prime example of this are the Pheidole soldiers with their massive heads (other examples are ants like Camponotus, Atta and the larger Solenopsis species).
0%2Bbrown%2Bhouse%2Bmajor%2Band%2Bminor%2Bpersp.jpg


Liam said:
The way that rufa queens found new nests is really interesting, we will have to add a disclaimer into the in-game wiki to point out that our rufa nests shouldn't really have self founded.
Formica rufa can spread by either budding off from the original colony (the queen returns to it's colony, takes a few hundred workers, walk a few dozen meters and founds a new nest that stays connected to and form some sort of colony network with the main hive and other offspring colonies), nesting somewhere near it's original colony (the workers of her original colony will find her and assist her, essentially this works s like the previous one) or she can take over a small colony of another Formica species like Formica fusca (the queen enters the nest, kills the queen and takes over the colony - usually the queen catches a lonely worker, kills it and rubs herself on it extensively to gain the colony scent of the colony she is going to invade).

You could just make the F. rufa colonies start with a few black garden ant workers (no egg tiles, so if they die they're gone) and it would fit perfectly (they could even have a limited life time, like die after 10 minutes or so).
 

Liam

Administrator
Staff member
Developer of EotU
[quote author=Serafine]
You could just make the F. rufa colonies start with a few black garden ant workers (no egg tiles, so if they die they're gone) and it would fit perfectly (they could even have a limited life time, like die after 10 minutes or so).[/quote]
Ha! This was basically the conclusion we came to today, great minds think alike :D

Also I didn't come across this info:
[quote author=Serafine]usually the queen catches a lonely worker, kills it and rubs herself on it extensively to gain the colony scent of the colony she is going to invade[/quote]
We were wondering how she did it. - Thanks for that wonderful image

Also, I will keep an eye on the word "polymorphic" in the game and try to only use it when the difference is clearly not just size based.
 

Serafine

Queen
Backer
Beta Tester
Ecosystem Beta Tester
Liam said:
Also I didn't come across this info:
[quote author=Serafine]usually the queen catches a lonely worker, kills it and rubs herself on it extensively to gain the colony scent of the colony she is going to invade
We were wondering how she did it. - Thanks for that wonderful image[/quote]
I'm not sure if Formica rufa actually does this but it's a common behavior of parasitic queens, so it's very likely she does. Ants communicate mostly via pheromones and fooling the workers is very important for the invading queens - it doesn't really matters if she looks different, she just needs to smell right.
Also parasitic queens usually have much smaller and flatter gasters when they fly (because they don't need all the resources to raise their own workers) and larger heads and jaws (to kill the host colony's queen and uprising workers).


Taking over a host colony however is a very delicate process and the chances of survival for parasitic ants are actually very very slim (even less than for regular ant queens).
Most antkeepers fail at introducing parasitic queens to a host colony even under the best circumstances, like when that host colony has lost it's queen. I've read an antkeeping journal where the host workers dismembered the newly eclosed workers (of the parastic queen) even months after they had accepted the parasitic queen. They cared for the eggs, the larvae and the pupae but as soon as the new workers eclosed the host workers' instincts kicked it and they tore the alien intruders apart before they could even harden their exoskeletons.
 

MikeSlugDisco

Community Manager
Staff member
Community Manager
^ This was why as a kid I put my foot in one, assuming it was a pile of dirt and leaves! I was put off vinegar for quite a while after that.
 

Serafine

Queen
Backer
Beta Tester
Ecosystem Beta Tester
Redmoth27 said:
I was thinking that you could find wood ants, IN TREES!!!
Most wood ants (and a lot of carpenter ants) like to nest in dead tree stumps. They then gather a lot of materials from the ground (leaves, needles, twigs, acorn shells, etc.) and create a huge anthill that covers the tree stump (they can grow up to 3+ meters in height).
Wood ants and carpenter ants are however active on trees where they milk aphids and other insects that suck from these trees.

This picture was taken some weeks ago when they had barely woken up from hibernation. Today half of the stump is covered in an anthill already.
zwfs6Sz.jpg



There are ants that live in trees (but only in the dead wood parts) but it's not too common for wood ants. Camponotus (and the tiny Temnothorax) also like to nest in all sorts of logs.
 

Redmoth27

Queen
Backer
I thought the player should have a sense of Veridicality so thing keep getting interesting with the terrain.
 

MBargo

Woo hoo!
Backer
Beta Tester
F. rufa is polymorphic but it is not that distinctive as Serafine said. There are a few kinds of polymorphism (I will try to translate): 1-phase allometry -Camponotus castaneus, 2-phases allometry -Atta texana, and three-phases allometry- Oceophylla smaragdina, total dimorphism - Pheidole fallax). All of that is decribed in E.O. Wilson's "The Insect Societeis".

Polymorphism means that two body parts (for example head width and pronotum (part of thorax) width) change ratio between them depending on growth of a worker. I suppose that F. rufa belongs to 1-phase allometry kind of polymorphism.

Beside that there is also monomorphism 8i (all body parts have the same ratio even if the ant is bigger than its sister).

--------------------------------------------
The short description of behavior related to size and age of the ant is shortly and nicely described here:

"Context-dependent specialization in colony defence in the red wood ant Formica rufa" - T.Parmentier, W. Dekoninck, T. Wenseleers

<page 162>
"Red wood ants (F. rufa group) are moderately polymorphic, displaying
a pronounced size variation (4.5e9 mm), but lack discrete
subcastes with shape specialization (van Boven,1977). Red wood ant
workers have been reported to perform different roles according to
both age and size (Herbers, 1979; Higashi, 1974; McIver & Loomis,
1993; Parmentier, 2010; Tanner, 2008; Wright et al., 2000). Young
workers nurse the brood (mainly small, young workers) or do not
participate in tasks (mainly large, young workers). Workers of intermediate
age are engaged in intranidal building (mainly small
workers) or repairing the nest surface (mainly large workers).
Finally, the oldest workers tend to forage for food. Small, old workers
are mainly allocated to aphid tending close to the nest, whereas
large, old workers mainly hunt for prey and tend aphids at larger
distances. Large red wood ant workers are more aggressive towards
conspecific workers (Batchelor & Briffa, 2011). Ant workers can
switch task depending on the needs of the colony (Holldobler € &
Wilson, 1990). However, foragers in red wood ants, in particular,
are rather consistent in doing their task (Parmentier, Dekoninck, &
Hendrickx, 2012; Rosengren & Fortelius, 1986)."


But.. the game cannot be that em.. let's say natural, I suppose ;)

More facts abouf F. rufa you can find in "Ants of Poland" page 72 (version from 2002) or ""British ants, their life-history and classification" page 241 (1915).
 
Top