Isopods come from almost every environment you can imagine. This means that different species may have different needs. Including their temperature range. Environmental conditions such as temperature, humidity, and habitat setup play a crucial role in influencing isopod health and behavior.
Isopods are ectothermic, so they can not generate their own body heat, unlike you or I. Meaning they have to practise behavioural thermoregulation. In general, this means they will move to warmer or colder areas to regulate their body temperature. Isopods are one of few if not the only crustaceans to make the jump permanently from the sea to the land. This remarkable evolution from water to land helps explain many of their modern temperature and humidity needs. In the oceans, and any large water body temperatures are consistent, meaning that for land-based isopods they haven’t evolved to be able to maintain their own temperature, or to be able to survive extremes of temperature..
Introduction to Terrestrial Isopods
Terrestrial isopods, often known as pill bugs, sow bugs, or roly-polies, are small crustaceans that have captured the interest of invertebrate enthusiasts around the world. These fascinating creatures belong to the order Isopoda and can be found in a wide variety of environments, from lush forests and shaded gardens to bustling urban spaces. With over 10,000 different species, terrestrial isopods offer an incredible diversity for hobbyists and researchers alike. Each species has its own unique requirements for temperature, humidity, and substrate, making it essential to understand the specific needs of the isopods you keep. Whether you’re caring for common pill bugs or more exotic species, guides like our beginners guide to isopods as pets can help you provide proper care to ensure their health and longevity in captivity..
How long is too long?
There is an important distinction to make here. By too cold are we talking one night when the heating failed, or regular temperatures? They are very different things. Add humidity to the mix and you’ve got a complex interaction. It is crucial to monitor and maintain appropriate moisture levels in the isopod enclosure, as improper moisture can lead to mold growth, dehydration, or stress, affecting the health and activity of your isopods. Cold air is drier than warm air, even if the percentages look the same.
Ideally, you want to mimic the microhabitat of your isopod’s natural range. It’s fine to look at the range of temperatures in say Thailand, but those aren’t the same temperatures as an isopod would experience in a small rainforest type environment in the mouth of a cave, and many species will do well when you focus on keeping isopods at room temperature with the right humidity and habitat..
How do they keep warm?
A primary way of staying warm is conduction between themselves and the surface they’re standing on. For reptiles, we tend to discuss the heat transfer from infrared radiation, but this relies on them being out in the open and basking. Many species of isopods don’t spend a lot of time out in the open, instead, they will be under cork bark or in the leaves, so understanding general isopod heating requirements helps you choose safe, gentle heat sources..
Air temperature is important, if it is too cold they will lose heat faster than it can transfer from the substrate. So it’s important to consider all aspects of the temperature. Including the fact that if it’s too cold they will burrow into the substrate to help preserve some heat. A slightly moist substrate is essential for isopods to burrow effectively and maintain proper humidity and temperature, and choosing the right method for heating pet isopod enclosures will make it easier to keep these conditions stable..
Studies on isopods and temperature
Studies on Porcellio scaber show that the growth of mancae, young isopods, at 15ºC was slower than at 22ºC but that their adult size was larger. At intermediate temperatures some toxins were safer, or at least less fatal. However at extremes of temperature there were more issues with bioaccumulation of toxins such as heavy metals. Maintaining optimal temperature levels is crucial for successful breeding and healthy development in isopods, and following a dedicated guide to breeding pet isopods will help you balance warmth, humidity, and nutrition for strong colonies..
As the temperatures drop isopods are shown to be slower when running, which makes sense given that their systems rely on external heat to keep things moving.
An interesting study showed that isopods that were exposed to fluctuating temperatures were more resilient than those maintained at a constant temperature. The temperature didn’t fluctuate more than a few degrees in each direction, but it shows there is no harm in a degree or two drop each night.
Cold vs. Temperate vs. Tropical
In a fair number of animal-keeping hobbies, we lump everything into three categories, cold, temperate and tropical, and isopods are no different. But the latter two only refer to locations on Earth. Not to temperatures. Peru is most definitely in the tropics, but parts see temperatures dip close to freezing of a night for a good portion of the year. Meanwhile temperate Australia can see temperatures that make the tropics look chilly.
In isopod keeping we only tend to worry about tropical and temperate. In general tropical species need higher, and more stable temperatures, temperate species will see a greater variation in temperature in the wild, and true cold species will see less variation, and yes cooler temperatures. It is important to understand the requirements of specific species, as different isopod species have varied temperature tolerances and habitat needs, so researching the needs of the species you are keeping is essential for their well-being, especially if you are choosing the best isopods for a planted terrarium where plants and invertebrates must share similar environmental preferences..
What is the best temperature for isopods?
There are too many isopods to mention here, but most species will thrive somewhere in the range of 20-27º, check out our shop for details on the best temperature for each species.
Some species can survive much lower temperatures, as low as 10ºC, and some even lower. So if the heating goes off for a night in your house your colony may survive unscathed depending on the species. However the activity of the colony will slow down, and breeding may stop. Maintaining warmer temperatures can help promote increased activity and successful breeding in many isopod species. This excess stress may cause other issues down the line, so keep a careful eye on things, particularly if you’re new to the hobby and still learning from an isopods beginner’s perspective about common husbandry pitfalls..
Temperature Requirements of Common Isopod Species
Tropical Isopods (Heat-Loving, Cold-Sensitive)
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Cubaris species (“Rubber Ducky,” “Panda King”)
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Optimal: 75-82°F (24-28°C).
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Too Cold: Below 65°F (18°C).
Maintaining high humidity, typically around 75-85%, is also essential for tropical isopods like Cubaris to support their health and breeding. -
Optimal: 72-80°F (22-27°C).
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Too Cold: Below 55°F (13°C).
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Optimal: 75-85°F (24-29°C).
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Too Cold: Under 60°F (15°C).
Temperate Isopods (More Adaptable, but Prefer Warmth)
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Porcellionides pruinosus (Powder Blue, Powder Orange, etc.)
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Optimal: 70-80°F (21-27°C).
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Too Cold: Can survive down to 50°F (10°C).
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Armadillidium vulgare (Magic Potion Isopods)
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Optimal: 65-75°F (18-24°C).
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Too Cold: Can tolerate down to 40°F (4°C)
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Porcellio scaber (rough woodlouse; a widespread, larger detritivore commonly used as a vivarium cleanup crew, notable for its inability to roll into a ball like Armadillidium species)
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(Dalmatian, Orange Koi, etc.)
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Optimal: 65-75°F (18-24°C).
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Too Cold: Can survive brief drops to 35°F (2°C).
Cold-Tolerant Isopods (Can Survive in Cooler Conditions)
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Armadillidium nasatum
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Optimal: 60-75°F (16-24°C).
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Too Cold: Can survive 35-40°F (2-4°C)
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Optimal: 65-75°F (18-24°C).
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Too Cold: Below 40°F (4°C)
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Armadillidium klugii (“Clown Isopod“)
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Optimal: 65-75°F (18-24°C).
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Too Cold: Can tolerate down to 40°F (4°C)
As the population grows, it is important to increase the enclosure size to maintain healthy conditions for cold-tolerant isopods.
Isopod Behavior and Social Structure
Isopods play a crucial role in their natural environment as detritivores, feeding on decaying organic matter and helping to recycle nutrients back into the ecosystem. Most species are nocturnal, preferring to stay hidden in dimly lit areas during the day and becoming more active at night. In the wild and in captivity, isopods are often found in groups, clustering together under leaf litter or cork bark to conserve moisture and protect themselves from predators. Some species even display fascinating behaviors like rolling into a ball when threatened, while others communicate through subtle chemical signals. Creating an enclosure with plenty of hiding spots, such as layers of leaf litter and pieces of cork bark, encourages these natural behaviors and helps reduce stress, allowing your isopods to thrive and display their full range of social interactions, as outlined in our beginner's guide to isopod keeping..
How to Protect Isopods from Cold Temperatures
Keeping an unheated isopod enclosure warm enough
You might be relying on the general room temperature to keep your isopods warm enough. But what happens if the heating goes out?
As soon as you realise put something over the enclosure to keep any remaining warmth in. A few towels or similar are a great option. When insulating the enclosure, make sure that ventilation holes remain unobstructed to maintain adequate airflow.
If you have access to warm water fill a container with hot water and put that under the towels etc. to add some warmth to the enclosure.
Keeping a heated isopod enclosure warm enough
If you have a heated enclosure and the heat source fails you can do the same, if the house heating is still on consider moving them to a warmer room. I find the shower room in my house is always a few degrees warmer than the rest of the house. There may be a similar space in your home. However, make sure the enclosure still provides shaded spots for the isopods to retreat from excess warmth or light.
Avoid keeping your isopods in drafts, or at the other extreme in direct sunshine. Extreme heat is as bad as extreme cold. Try and mimic what they would have in the wild, but avoid the extremes at either end and don’t forget that the climate has changed in the past century.
Isopod Health and Disease
Keeping your isopods healthy starts with maintaining a clean and stable environment. Isopods are sensitive to issues like mold growth, bacterial infections, and parasites, which can quickly take hold if humidity levels are too high or if the enclosure lacks proper ventilation. To promote isopod health, it’s important to regularly remove uneaten food, monitor humidity levels, and provide a suitable substrate that supports their natural behaviors. Avoid overcrowding your enclosure, as this can lead to stress and the rapid spread of disease. Stable temperatures and adequate airflow are also essential for preventing harmful bacteria and mold growth. By staying attentive to these factors and making adjustments as needed, you can help ensure your isopods remain healthy and active, and resources focused on isopod health and diseases can help you recognise problems early..
Conclusion
In summary, terrestrial isopods are captivating and rewarding pets for invertebrate enthusiasts of all experience levels. By understanding the unique needs of your isopod colony and providing a suitable substrate, stable temperatures, and proper care, you can create an environment where your isopods truly thrive. With attention to detail and a commitment to best practices, you’ll be able to observe their fascinating behaviors and contribute to their well-being in captivity. Whether you’re just starting out or expanding your collection, terrestrial isopods offer a unique window into the world of small crustaceans and the importance of responsible invertebrate care.
Further Reading
Abdel‐Lateif, H M, et al. “Interaction between Temperature and Cadmium Toxicity in the Isopod Porcellio Scaber.” Functional Ecology, vol. 12, no. 4, 1 Aug. 1998, pp. 521–527, besjournals.onlinelibrary.wiley.com/doi/10.1046/j.1365-2435.1998.00227.x, https://doi.org/10.1046/j.1365-2435.1998.00227.x. Accessed 5 Feb. 2025.
Dailey, Tara M, et al. “The Effects of Temperature, Desiccation, and Body Mass on the Locomotion of the Terrestrial Isopod, Porcellio Laevis.” Comparative Biochemistry and Physiology Part a Molecular & Integrative Physiology, vol. 153, no. 2, 12 Feb. 2009, pp. 162–166, pubmed.ncbi.nlm.nih.gov/19535030/, https://doi.org/10.1016/j.cbpa.2009.02.005. Accessed 5 Feb. 2025.
Schuler, Matthew S., et al. “Isopods Failed to Acclimate Their Thermal Sensitivity of Locomotor Performance during Predictable or Stochastic Cooling.” PLoS ONE, vol. 6, no. 6, 17 June 2011, p. e20905, pmc.ncbi.nlm.nih.gov/articles/PMC3117853/, https://doi.org/10.1371/journal.pone.0020905. Accessed 5 Feb. 2025.
Terézia Horváthová, et al. “Does Temperature and Oxygen Affect Duration of Intramarsupial Development and Juvenile Growth in the Terrestrial Isopod Porcellio Scaber (Crustacea, Malacostraca)?” ZooKeys, vol. 515, 30 July 2015, pp. 67–79, zookeys.pensoft.net/article/5768/, https://doi.org/10.3897/zookeys.515.9353. Accessed 5 Feb. 2025.
