Saturday, 20 January 2018

Profile of Odontomachus(Trapjaw ants) species in Singapore. Updated:12/5/2019

Profile of Odontomachus species of Singapore:

Brief description of Odontomachus Trapjaw ants
Odontomachus Trapjaw ants are under the subfamily of Ponerinae and are well known for having the fastest moving predatory appendage in the animal kingdom and their speed has been recorded to close at around 200 km/h . Odontomachus ants are also famous and easily identified in the ant-keeping community. They can be recognized for their medium to large size of around 1cm and above for most species and of course their notable trap-jaw which are held at 180 degrees when they are ready to strike that has a few small trigger hairs which when touched, the jaws snap down on whatever is unfortunate to be in strike zone. They also possess a sting which is quite painful and has been recorded to be a level 2 on the Schmidt's sting pain index. 
Image result for odontomachusOdontomachus Haematodus worker.
Care of Queens during founding stage
Trapjaw ants are quite a challenge to keep in captivity, especially for those who started out and are not sure what to do when they caught a Trapjaw queen. Trapjaw queens should be placed in a test tube setup with substrate as Trapjaws have "slippy feet" and can't grip on to your test tube material which is either plastic or glass, this stresses out the queen as she keeps slipping when she is trying to move. Another reason why substrate is important is that the larvae would use the substrate as a coating when spinning its cocoon and it greatly benefits the larvae. Personally, I do not like using normal soil for Trapjaws as normal soil could contain pests like mites and possibly toxic or parasites if coming from the outdoors. Trapjaws also like airy substrate if they were to dig, so normal soil is quite a bad choice, at least in my opinion. My preferred substrate to use would be peat and perlite (carnivorous plant growers would know what they are) as the peat is a good digging medium while the perlite helps makes the medium airy. Another good choice for an airy substrate would be crushed walnut shells although it is quite expensive. I've seen people had success using sand for Trapjaws during founding stage and mixed with crushed walnut shells when they are a bigger colony. 
Odontomachus queens are semi-claustral, which means they need to be fed during their founding stage to feed the queen herself and her larvae. I've heard people having trouble feeding their Trapjaws as they are picky eaters. But to me, they are very easy to feed. For a founding queen, you need to cut up any insects/arachnids you are going to offer to her as she would not only be afraid as the food is smaller than her, but also she will get to the insides easier and that's all the queen will ever eat. I use crickets for my Trapjaws and it works great. Trapjaws need to be fed every 1 to 3 days and you have to make sure you clear any garbage from previous feedings or mold will form. For sweet stuffs, Trapjaws do not really need anything sweet during their founding stage as offering honey in a test tube is quite troublesome (to me at least). But they do appreciate abit of honey if you were to offer them in either the test tube or outworld.

Polygyny and gamergates in Odontomachus
Odontomachus species in Singapore have been known to have gamergates for they are ponerines. But it is highly under studied other than the occasional observation of workers laying eggs. It has been recorded to be both fertile and infertile. Odontomachus are able to have multiple queens, this holds true for O.rixosus, which are a polygynous species. For the common O.simillimus however, it is much safer to introduce queens whom are sisters. I was able to form up to 8 queens before and any more introduction resulted in deaths. It is still best to raise them separately. 

Odontomachus species of Singapore
Singapore has a few species of Odontomachus. I only know of 3 species in Singapore which are, Odontomachus Simillimus (Common Trapjaw ant), Odontomachus Rixosus (Jumping Trapjaw ant) and Odontomachus Malignus. But most likely there is much more species waiting to be discovered.

Odontomachus Simillimus (Common Trapjaw ant): This is probably the most common Odontomachus species that most people have caught over here in Singapore. Odontomachus Simillimus are identified easily by their fully black bodies which have a red sheen under bright light. Workers can reach about 1cm in length and queens can reach a little longer than that at around 1.2cm. I currently have about 6 queens, 4 fertile and 2 infertile. I have no workers yet but I do have pupae for one of the queens. (sorry for blur pictures)

Pic 1 (left): Test tube setup for Trapjaws.

           Pic 2(right): De-alate queen of Odontomachus Simillimus with eggs, larvae and pupae.

Pic 3 (left): Odontomachus Simillimus
eggs and larvae.

Pic 4 (right): 
Simillimus pupae

Pic 5(below):
Alate queen of  Odontomachus

Odontomachus haematodus: This section has been removed for Odontomachus haematodus does not occur in Southeast-Asia and thus Singapore.

Image result for odontomachus rixosusOdontomachus rixosus (Jumping Trapjaw ant): Odontomachus Rixosus is currently one of the rarest ants in Singapore as no one from what I know has a colony and only a lucky few have spotted or caught an alate queen but had been unsuccessful in raising a colony most probably due to infertility. Odontomachus Rixosus is also one of the few ants being able to jump in Singapore, others include Harpegnathos Venator, similar to the Jumping jack Myrmecia of Australia. Rixosus are also easy to identify with their size being similar to Simillimus where workers are around 1cm and queens are a little larger, they are mostly orange and red in coloration with a little of black. Their jaws are also what makes them recognizable with about 3 frontal tooth on each mandible, with the middle teeth protruding. (Picture:Odontomachus Rixosus Queen and Worker.)
Odontomachus Rixosus are actually a polygynous species, meaning they are able to have multiple queens in the colony. Odontomachus Rixosus has been recorded living with Pheidole Tandjongensis in other parts of the world, not Singapore, for unkown reasons.
Care wise, I have obtained a small group of O. rixosus without a queen as an observation colony and housed them in a 45cm x 21cm x 18cm glass tank, with a diy formicarium, multiple wood, Fittonia plants and a soil mixture of 1:2:1 sand:peatmoss and perlite:shredded sphagnum moss. The colony was provided a varied diet of red runner roaches, house crickets, mealworms, protein jelly and mealworms. The "colony" was around 40 to 50 workers strong. I have noticed that their jumping abilities are rarely used when going about their daily duties, even in chasing prey which they would use surround techniques. I've noticed the workers were able to lay eggs as shown in the picture but due to the lack of males, the supposed gamergates were infertile. Here is the diy formicarium,I've made for them in it's initial state. I used cement bought from homefix to coat and adhere styrofoam to form sort of a cliff-side style and the same substrate mixture mentioned earlier. Make sure the cement dries!! In conclusion, I found that the key to Odontomachus rixosus is the pH of the soil. These ants come from soils as acidic as pH level 4-5, and it will be crucial to mimic their natural environment, coupled with plants and branches for them to explore. Med-High humidity is of utmost importance as well! This species also does not seem to be bothered by bright light, but it's best to provide them some darkness to mimic a forest floor condition This queenless and infertile colony lasted close to a year which is very long.

Image result for odontomachus malignusOdontomachus malignus: I only recently found out about this ant when I was doing a little search of Singapore's Trapjaws. This is quite an interesting ant as it is an inter-tidal species living along coastlines and in mangroves. This ant is able to swim to get to places separated by water, which makes it very interesting. Currently, no one has a queen or colony of this species in Singapore. But from what I know, Workers are around 8mm and have a similar appearance to Rixosus but redder coloration. (Picture: Odontomachus Malignus swimming)

Odontomachus pararixosus: This is the mysterious "rixosus subspecies" that took me a while to research and find out. Here are the differences from my own findings.
O. pararixosus: The 3 frontal tooth of the mandibles are aligned unlike O.rixosus, the middle tooth isn't sticking out and it is smaller than the two teeth surrounding it. It has mostly around 7 smaller denticles along each mandible.

Odontomachus rixosus:
Middle frontal tooth is sticking out and around the same size as the two adjacent teeth or bigger. Has about 5 denticles along each mandible.

*Please do contact/ credit me if you were to use any of this information or have any new findings to discuss!
Setups: Trapjaws can be housed in a variety of setups like formicariums and substrate setups. One thing to note when setting up an enclosure for Trapjaws is that they are prone to raids by smaller ants such as Ghost ants (Tapinoma Melanocephalum) so defences like barriers, a cover or a moat would be effective if a raid were to happen. For substrate setups, make sure you do not use normal soil as stated in the queen ant care section above. Substrate mix like peat and perlite or sand and crushed walnut shells would be great for Trapjaws as they like airy substrate. For formicariums, Ytong is the best for Trapjaws as they are able to grip on but due to having slippy feet, acrylic is a less preferred choice. But do any setup you wish to experiment with your Trapjaws, I plan on doing an island setup with a moat surrounding it for my future colonies.
Well that's it for my Trapjaw profiles, it is my first ever blog so I apologize if it's a bit weird. Any mistakes in the post or questions you would like to ask please email me. Thanks for taking the time to read! Hope you have learnt a thing or more from this post and enjoyed it! - Isaac Ong

Citations: Odontomachus haematodus worker picture: Retrieved January 20, 2018, from

Odontomachus Rixosus picture: Retrieved January 20, 2018, from

Odontomachus Malignus swimming picture: Retrieved January 20, 2018, from


  1. Wow..!!
    One of the best articles, in my opinion.
    Just few days ago, II starte with Odontomachus: she gave an egg..!!
    However, she passed away two days later. And left the orphan egg..
    I have other colonies, different species, and this is my first loss.
    Thanks for all the Tips,
    Small things make big differences.

    1. Hi, sorry for the late reply! Losses are alright in the hobby and I know it's sad. Losses are how we learn! I hope my blog will help you for your future ants :)

    2. Thanks a lot,
      It's more than help, it's a real guide,