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Introduction & Overview

I love keeping C. fragilis because of their unpredictability. Each ant has its own personality, and all of the workers have a ton of energy. While the ants are not exceptional at bypassing barriers, if they're stressed out, they can run very fast. At a certain point, this species starts growing as much as you feed them. This means the colony will grow a lot faster based on how much protein they are given. They grow faster than other Camponotus species.

Because of their fast growth and easy handling, C. fragilis are the perfect species for beginners. However, once a colony gets too large, ant-keepers should also keep in mind how they will continue to feed, nurture, and house these ants.

Common Name

Queen Size

12 mm

Worker Size

7 mm


Beginner Friendly
Fully Claustral
Major Caste

🛠️ Help Requested

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Queen Identification

Right off the bat, Camponotus fragilis will be easily identifiable, as it is one of few species of ants in its region with a full yellow integument (Photo 1). The queens measure from around 12mm to 15mm, depending on how much food they have stored inside (Photo 2-4). As the colonies are nocturnal, workers, such as the ones in the pictures above may be found while looking for queens as well.


There are a few other ants which have the same bright yellow as C. fragilis, such as some Myrmecocystus species. However, these can be differentiated from from Camponotus species easily. Myrmecocystus workers have 2 humps on their thorax, whereas Camponotus workers generally only have 1. Myrmecocystus also generally have more triangular heads.


C. fragilis are part of the festinatus complex and may be mistaken for C. absquatulator or C. festinatus. C. festinatus can be differentiated from C. fragilis due to their overall size. C. absquatulator minor workers lack erect hairs on the head present on C. fragilis workers.

Founding setup

If the queen is infertile, she may not lay eggs or will constantly eat the eggs she lays. On hot days, infertile queens will try to escape from their setups. C. fragilis have a very high success rate during founding. With the proper care, over 95% of fertile queens will be able to get workers.


Camponotus fragilis are fully-claustral and thus do not need to be fed before they get workers. New keepers often make the mistake of checking on queens too often. While this is not a serious issue with C. fragilis, queens may cannibalize their brood if stressed out too much. However, I would recommend at least checking on the ants twice within the first week to make sure they have settled down and that they have everything they need.




85f (29c) in a gradient



Generally, ants will choose to move their nest to the place that suits them the most. Camponotus can be described as semi-nomadic, as the large colonies often have multiple satellite nests between which the queen and brood will constantly traverse. If an area is too hot or cold, the ants will avoid it. Camponotus are able to retain their moisture very well, and in my experience, they only need drinking water to maintain their humidity. C. fragilis are also desert ants and are accustomed to lack of humidity.


From my experience, C. fragilis will place their brood between 75-85F (24-29C).

Time to first workers

5-8 weeks when heated at 85f with gradient

Sensitivity concerns

Queens should take no more than a week to settle in their nest. However, if they are removed and taken to another nest, it will take more time for them to settle down again. Once the queen starts laying eggs, that's a pretty good indication of her settling down and accepting the nest she has been provided.


It will take around 5-8 weeks for C. fragilis to get workers. Camponotus colonies usually start out slow. Brood production depends on how motivated or stressed the queen is. C. fragilis will usually have smaller nanitic batches than most other Camponotus species, but they also grow very fast.

Tubs and tubes

Camponotus fragilis are very active ants, especially at night. When they are hungry, they will be constantly at the cotton, which means having an outworld or a tub and tube colony setup helps a lot with caring for them. Otherwise, keeps may experience problems such as having to deal with escapees all the time.


The ants will need both a source of protein and sugar right when they get workers. From my experience, these ants do not have very large nanitic batches, but after the first workers eclose, they start producing a lot of brood. Some sources of sugar for C. fragilis include honey, sugar water, byFormica sunburst and perky pet hummingbird nectar. You can feed them protein by giving them small insects like fruit flies, or cut up roaches and mealworms. They also enjoy eating soft-bodied spiders. Other sources of protein that have worked well for me in the past include rehydrated Hikari Freeze-Dried Bloodworms. Occasionally, the ants will also take some chicken or other human meat if no insects are available.


It's very important to cycle through different foods for the ants, as one type of food is not enough for them to obtain all the nutrients they need. For example, I would switch around the type of protein I feed them every other time, feeding fruit flies one day, and bloodworms the next. I would make sure that the ants have constant access to sugar when they need it and feed protein every other day. While the small colonies may not eat much, it is still important for them to have access to a steady source to keep up brood production.


Any setup would work for C. fragilis as long as they have both a nesting area and a foraging area. Unlike some other ants, they are not very picky about where to live. Early deaths in colonies of C. fragilis are not uncommon, but should still be noted with care. Causes of deaths may include poisoning, and it is important to trace any symptoms back to its source.


Fluon has worked as a containment barrier for me in the past. Other barriers, such as pipe sealant have also worked. However, the ants are also very persistent in climbing, and they may simply leap over the barrier or find a workaround, so barriers should be observed and fixed if needed every month.


I've had the most success with feeding sugar through liquid feeders because the ants have a tendency to bury sugar water if they are unable to drink all of it. This means that if there are open sources of liquid, they may pull apart the cotton in their tube to cover it up, which could lead to the cotton collapsing and drowning the ants.


Substrate is not necessary for keeping C. fragilis since their brood can form pupae without it. However, it is still helpful, just in case the water in their tubes leak and threaten the brood. I would make sure to heat the colonies with care, as the ants will try to move their brood away from sources of heat if it is too hot. If they move their brood onto the cotton in the tube, it may damage the pupae, which have to stay dry.


C. fragilis grow very fast for Camponotus species, but they are also very easy to handle. Once they outgrow their test tube or tub and tubes setup, there are a variety of options open for further expanding the colonies. One option would be to simply make a bigger tub and tubes setup that has a greater capacity, or you could consider moving them into a formicarium.


For C. fragilis, hydration of formicaria is ultimately not very important. In my experience, they obtain pretty much all of the moisture they need through drinking water, and the brood prefers dry areas over humid areas. I would recommend purchasing a TarHeelAnts formicarium once the ants surpass 100 workers or a Camponotus hybrid formicarium from AntsCanada once they reach 200 to 300 workers. These formicaria give the ants a less stressful place to nest and expand their colony compared to tub and tubes setups, where the foraging areas are usually frighteningly close to the open tubes, where the ants nest.


After the colony reaches more than 1000 workers, a large tank formicarium setup might be suitable to give them space to grow, because as long as they are being fed, they will continue to grow very fast, increasing by the hundreds every month.


Link to a very successful journal:


Some research surrounding C. fragilis:

Consistent self-organized foraging allocations in the macronutrient-regulating carpenter ant, Camponotus fragilis

The Gut Bacterial Communities Associated with Lab-Raised and Field-Collected Ants of Camponotus fragilis (Formicidae: Formicinae)


Useful information for identifying C. fragilis in the festinatus complex:

Taxonomy of the Camponotus festinatus complex in the United States of America (Hymenoptera: Formicidae)


C. fragilis are extremely popular among Californian ant-keepers. Many ant-keepers admire them for their lovely yellow color.




Final Thoughts

I encourage anyone who can to keep this lovely species! They're extremely cute and very enjoyable :) ❤

Camponotus fragilis

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