It’s not often that we learn about animals that commit suicide, but some ants and termites have evolved to have an explosive suicide as a defense mechanism to protect the colony from larger intruders.
The scientific term for this behavior is autothysis, which can be translated to “self sacrifice”, and has so far been seen is a few different species of both ants (Family Formicidae) and termites (Infraorder Isoptera). However, the phenomena has been best studied in colonies of ants, so this is what we will take a closer look at in this post.
Camponotus saundersi. Image by Bernard DUPONT, posted with the Creative Commons Attribution-Share Alike 2.0 Generic license.
The ants who have evolved this type of defense mechanisms have all been found on the island Borneo in Southeast Asia. The first species with this ability was discovered in 1935, and got the name Camponotus saundersi. So far all species with this ability has been arboreal ants, meaning that they are living most or all of their lives up in the trees in the jungle, where they use this mechanism to fend off other (larger) species of ants and other insects that poses a threat to them.
How the ants explode to protect the colony
When an exploding ant such as Camponotus saundersi realizes that the intruder it is facing is likely to win the fight, it goes into the self-destruction mode by having violent contractions on its abdominal muscles. By doing this it will rupture a part of its abdomen, which in turn will lead to the oversized mandibular glands bursting.
The mandibular glands are filled with chemicals, and these will be released from the front of the head of the ant when they burst. The chemicals are composed of polyacetates, aliphatic hydrocarbons, and alcohols, and are both corrosive and able to entangle all nearby victims.
Since parts of the abdomen is ruptured during this defense mechanism, the ant obviously dies from performing it. It's a bit grotesque, but this sticky explosion will be a big problem for the invaders or predatory insects who wants to get in to the colony, so it's a great defense for the colony as a whole. But why would an animal choose to perform suicide to protect the colony? This is a pretty complex subject that I could write several posts about, but we'll get to take a quick look at the big strokes of it.
Another image of the Camponotus saundersi. Image by Noel Tawatao / www.AntWeb.org, posted with the Creative Commons Attribution 4.0 International license.
Why it makes sense for the ants to kill themselves to protect the colony
Altruism in animals is a big and kind of controversial topic that I won’t be discussing in depth today, but the thing we know for sure about this topic is that we often see it in eusocial insects - insects that have complex social behaviors, including castes such as sterile workers.
These sterile workers are obviously unable to reproduce themselves, so in order to increase their fitness, they must work on increasing the inclusive fitness, which means that the offspring of related individuals are counted for, since these share many of the same genes.
You would share 50 % of your genes with your own child, but only 25 % of the same genes with your siblings offspring, meaning that it would give you a better overall fitness to make sure three of your siblings’ children survive to grow to adults compared to making sure one of your own children would (assuming you had to pick one).
It might sound really strange, but eusocial insects that are unable to get their own children have to depend on this inclusive fitness, and to make it even better for them, most of them share up to 75 % of the same genes (because they will get more genes from their mother - the brood queen), meaning that they get a big benefit from helping the colony survive.
By saving the colony it also prevents its sisters and mother from being attacked, which helps ensure that many sets of the shared genes are passed down to another generation.
This little introduction barely scratched the surface of the interesting topics of eusocial insects, and alternative ways of increasing the fitness of an organism, but hopefully you guys understand what I’m getting at with this.
The point is that the sterile workers of exploding ants are gladly willing to sacrifice themselves to protect the colony, and can even increase their inclusive fitness by committing suicide.
A new exploding ant species has been found
Ever since the first species of exploding ant was discovered in 1935, scientists have been searching the Bornean jungle for more species with the same behavior. Some new ants have been found, but due to taxonomic challenges (it’s not easy to do taxonomic studies on insects with castes that look unlike other castes of the same species), no new species has been officially described until this year.
Back in 2014 a research team from several different countries worked together to learn more about autothysis, but instead found enough evidence to describe a completely new species of exploding ant, the aptly named Colobopsis explodens. Up until this point it had been referred to as being a member of the Colobopsis cylindrical species group, that most likely has several different species of undescribed exploding ants within it.
So now we have two described species of exploding ants, but as the paper suggest, there could be many more new species lurking within the Colobopsis cylindrical species group.
Find strange defense mechanisms interesting? Check out the lizard that squirts blood in the face of its predators!
Thanks for reading
I hope you enjoyed the post about the exploding ants (and termites although we didn’t get into details about those). I think this is a really cool defense mechanism, but I’m also glad we don’t see it in any bigger species, because that would be messy. Hehe. Anyway, thanks for checking out the post!
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Hey, I'm @valth - the author of this post. I love to write about nature, biology, animals, nature conservation, ecology and other related branches of science, and I occasionally write about my life, about Steem or about random stuff as well. I'm trying my best to write at least one post every day, so make sure to give me a follow if you enjoy my content and want to see more of it.
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This defense mechanism and suicide for the sake of protection of others is very different and new for me.
Well, it's a pretty rare mechanism, so it's no wonder that it's new to you ;) Very few animals got anything like this in their arsenal of defense mechanisms!
Oh, now I already know why Kamikaze committed suicide, those mischievous ants were guilty of inspiring them to do it, and guess what? they are both Asian, coincidence? I don't think so.
Well, now talking seriously. The colony of ants has always been more important as a whole than as single individuals, if you put a group of ants together in a jar(I did this as a child), most of the time they will try to escape instead of fighting. But if you put a group of ants on another ant's nest, it will be a bloody fight. Never mess up with ant's colony, because that's what they care the most , and they are like vikings, they will fight till' death.
Couldn't find an explicit and detailed video about ants "exploding", but as far as I see, they basically tear themselves apart to expel a toxic liquid and kill their enemies.
If we talk about exploding and expelling toxic gases, this is the first thing that will come to my mind. (if you ever played left 4 dead you will understand)
Haha awesome association!! :D
haha thank you.
Were the ones in the jar from the same colony? Is so, this also ties nicely back to the point about inclusive fitness, where the ants will work together with its relatives (colony mates) because they share genes, so it's beneficial for them if the other ants also survive. But they don't share many genes with ants from other colonies, so they will have no problem with slaughtering them.
If you jar ants from several different colonies together, it becomes a bit more complex to explain why they work together :P Hehe
Ah, little kamikaze ants. I get it though.... Ants are one of the few insects considered to be "super organisms," so it makes sense that they would have this kind of function. They don't function on an individual basis, but instead, as if a single being. I believe that bees exhibit the same kind of behavior, but don't actually explode (even though it's quiet the display to intruders.) It's funny the kind of things that nature has up it's sleeves!
Yeah, exactly. That's a pretty good summary of eusocial insects.
A lot of bee species die when they sting another animal, so that is absolutely a good example of the same type of altruistic behavior where it dies to protect the hive.
Very clear explanation of why it makes sense for them to do this from a gene preservation point of view. There are other situations where ants sacrifice their life for the colony right? Like forming the bottom layer of a rafts for the colony to cross a river. I think I have seen a picture of that happening
Yes, most species of ant have castes that are willing to die for the greater good of the colony. Most don't have to directly sacrifice themselves for the colony, but instead put themselves in great risk in order to protect the others.
Very enjoyable read! I have read about ant altruism in various books by renowned myrmecologist Bert Holldobler. I've heard of ants that spray formic acid (with no damage to themselves) but never about anything that blow up like this. I would love to see some videos of this on a macro level. Do any exist?
It would certainly be very interesting to see a video of it, but I have not been able to find one. Let me know if you ever come across one though ;)
I don't have anything really good to contribute to these comments, but you know that the mechanics of indirect kin selection and cheating are some of my interests. Just wanted to thank you for posting this.
I'm glad you liked the post, @effofex! It's for sure an interesting topic, and I remember that I was really intrigued when I first learned about it during my bachelor's studies. It's just so cool that it can be used to explain a lot of behavior that would otherwise make very little sense to us.
Indeed, it is an astonishing process of protecting the colony!
Ants are fascinating insects, it reminds me when young, I read the trilogy of Bernard Werber.
Their multiple societal behaviors, such as nest creation,
communication, survival, make it one of the most interesting insects to have studied
Your research is very advanced and it's always a pleasure to read you,
you allow us to learn so much.
It made me want to reread books on ants!
Thank you.
Resteem always excellent articles.
Thanks for the kind words, and the resteem! Ants are indeed very cool creates, and I am actually working on another ant post that will probably be posted in the next few days ;) There's just so much cool stuff to write about when it comes to ants!
Oh, genial!
I am looking forward to your post. 😉
this is shocking to me 😮😮.for protection of their community they are ready to die means suicide really never listen and read about this before. this is pure new and quite strange article for me. actually big thanks to you sir you are actually educating people.immense respect for you. this is one of your best posts indeed.........
I'm happy to hear that you liked it, @xawi! It can be pretty strange for us to comprehend how they would be willing to commit suicide to protect their colony, but just keep in mind that eusocial insects are a lot different to us humans; the entire colony acts almost like a single organism.
I'm confused how I could have no heard of exploding ants in all my years obsessed with learning about them. They're just so damn diverse!
Yeah, they are an extremely diverse family, so I can see how it would be easy to miss out on some of the interesting ones, especially when you consider how messy the taxonomy can be for certain genera can be as well.
Selflessness at its best....
Such complex community interaction, amazing!!!
In case of threat does one member commits suicide or does multiple members participate in it???
As far as I understood, it's an act that is carried out by single defenders. The substance that explodes will reach the surrounding area close to the exploding ant, so it would probably hurt the other ants as well if they explode while being with more members of their own colony.
Very nice article! I never heard about this kind of self-sacrifice in the animal kingdom. For me it seems kind of weird, that their own muscular equipment is capable of ripping up their own body! :O
Well, it's a very unique and rare ability, so it's no wonder that most people have not heard of it before. Hehe, just imagine how ripped their abs must look!
Oh my, now i'm jealous thinking about those ant abs. Another life situation I would have never expected to come up! Haha! :)
Haha! :D
Wow, I thought bees are the only group that willingly commit suicide to attack opponents. I did not know that it was a more common trade in the insect kingdom.
I would probably not go as far as calling it common though. I don't think we will ever find this behavior outside of eusocial organisms, and it's still rare within this group as well. But who knows? We might end up finding more species who does this in the future.
Wow some amazing facts about the sacrifice of ants and termites. They also follow the footsteps of humans. Their effort for their group is laudable. Thanks for sharing @valth
You're welcome, @kamchore :) I'm glad you found it interesting!
Will their colony comrades give honor for their unselfish sacrifices too? Just kidding.😂
Thanks for sharing this information @valth. 😊
Hehe, that's funny :P
You're welcome, @realnairda.
wawoow this fact about the explosive suicide of ants termites is new for me and really special that animals also sacrifices their lives for the protection of their community really nice to know that family and society is really speical for everyone @valt
I'm glad you learned something new from the post, @akashhassan ;) Thanks for stopping by!
Yeah I knew it that some insects do that but of ants this was new for me. Species are of different kind some eat their own family members to remobe their hunger and some explode themselves in order to protect them. Great post
A great protecting step for the colony..well desesrve
Yeah, there's a lot of "crazy" behavior in the animal kingdom for sure!
That's quite an interesting information about Aunts.
never heard of it before!
Camponotus saundersi is quite an interesting name for aunts.
thanks for the information.
I'm glad you learned something new then :) Yeah, that's a cool name, but I have no idea what it means though.
:)
When the ants feel that they are dying and die, the body of the ant produces an item that the other ants feel. It kills the sick ant, which is called suicidal, to protect the colony of ants from any other insects that may threaten the life of the colony.
All the best for you 😃😉 Thanks you for sharing a good information , good luck my friend @valth 👍👍😉
Thanks, I'm glad you liked the post, @samer484 :)
And now we talk of exploding ants, quite a sacrifice and how they have the feeling they owe that to the colony still keeps me amazed, and there are two species now, wired fact about an ant, I just keep getting stunned by nature. Nice one @vault
Thanks, I'm glad you liked the post. It's a pretty strange world out there ;)
wow, thats some defence mechannism
Yeah, it's pretty amazing.
That's why living in groups in necessary. It has got many benefits.
Sure, that's true.
Living groups is very essential for human
thanks for your nice post
Yes, that is true, but I don't see how that's relevant to the post.
Informative
I'm glad you think so.
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