Indoor Accommodation for Tortoises: A Practical Guide

A typical glass-style 'tortoise beginner kit' as often recommended by pet stores. This is, in reality, far too small, fails to offer a suitable thermal environment and also includes unsuitable substrates, inadequate lighting and heating, a poor quality unreliable thermometer and damaging pellet foods. Sadly, however, thousands of new keepers are mislead into purchasing combinations such as this. Tortoises raised in such units have incredibly high rates of metabolic bone disease, deformity, and rarely survive beyond a few years.

It is really important that we say at the outset when discussing this subject, that with very few exceptions (which we will explain below) all of our experience of working for 40 years with literally thousands of rescue and rehabilitation cases, and a similar period studying tortoises in the wild all over the word, leads us to conclude that tortoises should never be sold or acquired on the basis that they are suitable to live exclusively indoors. In all cases, as much time outdoors as possible in a suitable enclosure and with access to natural, unfiltered sunlight should be provided.

The eventual adult size of the species in question also has a massive impact upon what is viable in your particular circumstances. If you want to keep African Spurred tortoises (Centrochelys sulcata) or Leopard tortoises (Stigmochelys pardalis), you would be best advised to live in a warm, dry climate, and be prepared to devote a huge amount of space to the animal. If you live in a small house or apartment in Northern Europe or anywhere else with a similar climate, you should avoid species like this. Conversely, if your interest is in keeping tropical, high humidity species such as Redfoot tortoises (Chelonoidis carbonaria), you need to understand that no matter what efforts you make, you will never achieve truly optimum housing unless you live in a semi-tropical environment and can devote a lot of space out of doors to creating a secure pen. Everything else will be just a compromise. You will struggle with providing enough space, maintaining suitable humidity levels, and especially - these days - the incredibly high energy bills that are involved when trying to maintain them. One keeper of large tropical tortoises in the UK recently told us that they estimated the annual cost in electricity bills alone at over £3,500 (approaching $5,000 US). Even with small species, these costs mount up rapidly. For example, a simple pair of 100W heat lamps plus two UV-tubes can easily cost upwards of £25 per month in energy bills. This point does need to be stressed, because some sellers will certainly try to convince you otherwise. Don’t fall for it. This is one reason we now see many such animals up for rehoming, or even worse, just 'dumped'.

Mediterranean tortoises

Our strong recommendation is that Mediterranean tortoises must also have access to well-designed and suitable outdoor pen-type accommodation, with the addition of 'mini-greenhouse' units to provide a much needed boost to temperatures in colder weather. Such designs have a proven track record of working extremely well even in quite cold locations such as the North of Scotland and Scandinavia. They provide very high quality environment and a high quality of life. See our detailed guide: "Practical outdoor habitats and pen design in colder climates".

An indoor enclosure may be required from time to time on a temporary basis, however, for use with sick animals during treatment, or with species that do no brumate (hibernate) over winter such as Egyptian tortoises (Testudo kleinmanni) or Tunisian tortoises (Testudo nabeulensis). In such cases it should offer the maximum possible floor space, and be equipped with high quality lighting and heating that is installed correctly. Small, enclosed vivaria should be avoided and very large custom-built units or open-topped tortoise table designs should be used instead.

In the UK, the Animal Welfare Act (2006) established some important principles that all accommodation intended for captive animals must be measured against. In other countries different laws - or no laws at all - may apply. A formal duty of care now exists upon all persons responsible for animals in captivity. The Act says that an animal’s welfare needs include:

• a suitable environment (how it is housed);

• the ability to exhibit normal behaviour patterns;

• any need it has to be housed with, or apart from, other animals; and

• protection from pain, suffering, injury and disease

  
  

Any vivarium or other indoor tortoise enclosure or habitat that is sold to be used with tortoises should comply fully with the relevant legislation and should be fit for purpose. It should be safe, and when used as directed, it should produce a suitable environment that meets the animalʼs physiological needs.

People are often persuaded by pet shops that it is "easy" to keep tortoises indoors and that tortoises are suitable animals to be kept indoors . It is not, and they are not either. It is extremely difficult and few succeed long-term.

Three types of housing are often suggested.

We will describe these different types of housing briefly and outline the most common problems associated with each.

Glass tank-type vivaria

Although heavily promoted by the pet trade (because they are an additional, high profit-margin sale) units like this are completely unsuitable for Mediterranean tortoises. Avoid!

The main defects of this type of housing include:

• Severely restricted floor space, resulting in stress and lack of exercise

• Poor ventilation

• Inability to provide adequate thermal gradients

• Tortoises become frustrated by glass walls

• Total reliance upon artificial heat and UV-B (glass blocks all natural UV-B)

• Difficult or impossible to provide truly adequate lighting and heating

• Difficult or impossible to achieve adequate substrate volume and microclimates. Many species have an instinctive need to dig and to burrow.

• Heavy, fragile and extremely expensive for the tiny floor area they provide

• Lack of 'interest' and boredom. Tortoises that are kept in small enclosed tanks tend to exhibit lethargy (inactivity) and other unnatural behaviour patterns. By contrast, tortoises in suitable outdoor enclosures, or suitably large and well-designed indoor enclosures, will be much more alert and active.

• Hygiene. Enclosed vivarium-style enclosures tend to be difficult to maintain, and pathogens can build up very rapidly. This is another reason that we see so many sick animals that have a history of being kept in such accommodation.

The Tortoise Trust conducting objective temperature measurements on a glass vivarium sold for use with tortoises. It failed every criteria. Other measurements were taken of UV-B and visible spectra lighting. It failed those too. All units of this design perform equally poorly.

Tortoises kept in this kind of unit are frequently lethargic, dehydrated and at at considerable risk of bladder 'stones' and renal failure. The lack of ability to dig to create burrows and microclimates is one factor in this. Another is the often extreme temperatures measured directly under the basking lamps (in one test we recorded 72°C (161°F) with barely any genuinely cool area within the confines of the tank to escape.

Juvenile African Spurred tortoises (Centrochelys sulcata) on display in a glass vivarium in a pet store. Their eyes are closed. They barely moved. They are dehydrated, overheated and on an unsuitable, intensely desiccating pellet substrate.

Wooden enclosed vivarium

A very common design. Unfortunately it is also entirely unsuitable for tortoises. Units like this result in a depressing and constricted living space that completely fails to offer an acceptable quality of life. They are also highly problematic due failures to provide an appropriate thermal environment and the very close proximity of damaging heat artificial sources to the tortoise confined inside.

The main defects of this type of housing are identical to those of glass tanks with the exception that they are not as fragile:

• Extremely expensive for the tiny, restricted floor area they provide

• They are particularly dark and 'dingy' compared to outdoors even with their artificial lamps tuned on

• Overall performance is extremely poor and in our opinion they do not meet even the bare minimum standards on health or welfare grounds

A typical example of this type of vivarium in use. Note how uneven the lighting is and how dark it is away from the focal point of the heat lamp. The substrate is unsuitable, the floor area is minimal, and there is no possible way that this unit can provide an acceptable environment.

Other very common problems with ´tortoise starter kits´ and similar combinations as typically sold online and in pet stores include:

• Poor quality accessories such as cheap thermometers that produce totally incorrect and misleading readings

• Unsuitable or under-powered lighting, for example, "UV Basking Lamps" that produce no UV-B, but only UV-A.

• Poor quality or very low powered fluorescent tubes that are incapable of providing enough UV-B

• Inclusion of underfloor heat mats that are not appropriate for use with tortoises and that can cause severe burns

• Inclusion of damaging, highly processed commercial pellet foods that are poorly formulated and cause growth deformities. On that topic refer to our in-depth report "The Weird, Wild World of Commercial Tortoise Foods" - which we were threatened with legal action over in an attempt to shut down!

• Inclusion of completely inappropriate or dangerous substrate material (hemp, beech chips, coco coir, etc.)

We have spoken to dealers and traders about this, and they have stated quite openly that the main reason they heavily promote such setups is that they are extremely profitable and that there is such good potential for ongoing repeat sales of expensive substrates, accessories and packaged foods.

Once the tortoise or equipment has been sold, dealers know that it will likely be quite some time before the consequences become obvious, and by that time they cannot be held in any way responsible.

Tortoise Tables

Of the three options, these are by far the best, although we would still not recommend them for full-time, exclusive use. They can provide useful and effective temporary accommodation, however, as shown here for use with sick tortoises or for similar shot-term indoor use.

Disadvantages:

• You may well have to make your own, as suitably large units are not often available commercially. They are quite easy to construct, however.

• They suffer the same disadvantages as all indoor accommodation. Reliance upon artificial light and heat, lack of space (compared to outdoor housing), and it can be difficult to achieve an adequate depth of substrate (though see above link for some good ideas on this).

Advantages over enclosed vivaria:

• Much better ventilation (though not as good as outside, of course)

• Much easier to install flexible higher quality options for light and heat using overhead supports, such as full-length high output UV-B tubes or adequately powered basking lamps

• They can take advantage of at least some visible spectrum natural light, but do note that window glass will still block all UV-B.

• Very much larger usable floor space vs. most enclosed units

• Cost effective and easy to construct and not easily susceptible to accidents

It is important to address the false claims often made that tortoise tables "get too cold" or "cannot provide warmth overnight". Neither is true. Using a combination of ambient background heating and the correct type and power of basking sources perfectly adequate temperatures can easily be achieved at any time of day or night. In connection with overnight temperatures, many people have completely incorrect perceptions about what is natural and safe, for example. For Testudo hermanni, Testudo ibera, Testudo graeca and Testudo horsfieldii overnight temperatures of 5° Celsius or 43°F are perfectly safe and indeed are several degrees higher than what they routinely experience in the wild in early Spring. Certainly if you maintain a minimum of around 10°C or 50°F you will have no problems at all and a large margin of safety. Effectively 'cooking' the tortoise at minimum temperatures of 20°C or above around the clock results in an unhealthy accelerated metabolism, excess growth and very high levels of metabolic bone disease.

A typical example of a tortoise (Testudo marginata) raised in an indoor vivarium 'tank' at excessively high temperatures and with zero access to natural UV-B. The thickened keratin, extreme rate of growth and deformity is classic of excess exposure to damaging, dehydrating artificial heat sources deployed in close proximity.

Two juvenile Testudo hermanni demonstrating the exact same effects. Similar history. Reared from hatchlings in an enclosed vivarium. The substrate here is comprised of hemp which is totally unsuitable and has been associated with numerous serious injuries and deaths.

Comparison: Healthy captive-bred Testudo marginata of the same age as the deformed example that was raised in an enclosed vivarium. This example was raised using a combination of outdoor pens and greenhouse accommodation in the UK.

The effects of artificial light and heat

An unavoidable aspect of keeping tortoises indoors invariably means a heavy reliance upon sources of artificial lighting and heating. Unfortunately, many of these artificial sources have serious problems. In general, modern high quality UV-B tubes are usually safe (and if used correctly) are effective.

Typical effect of a tortoise attempting to bask under an artificial basking lamp. A small part of the surface gets too hot while the rest of the animal remains too cold.

Artificial sources of infra-red, however, are far more problematic and their use is linked to a number of serious side-effects. This is a complex subject and we refer you to our detailed report on the matter "How Heat Lamps can Harm the Health of Tortoises and Contribute to Growth Deformities". Minimising exposure to such lamps is highly advised, and even if heat lamps are used some of the time, the more you can do to reduce their use and increase exposure to unfiltered sunlight the better.

Thermal Biology

Tortoises are reptiles, and therefore rely almost exclusively upon the environment that they are kept in to meet their physiological and metabolic needs. This means that they must be able to attain adequate temperatures to permit normal activity patterns, and must be able to self-regulate their temperature using the environment provided. This is called behavioural thermoregulation. This requires a range of different temperatures to be available to them. The difference between the highest temperature in the habitat and the lowest is called the thermal gradient.

The exact temperatures and gradients needed vary greatly according to species. Here, we will restrict this to Mediterranean tortoises such as Testudo hermanni (Hermann's tortoise), Testudo graeca (Spur-thighed tortoise and related subspecies) and the Asiatic Testudo horsfieldii (Russian tortoise) that has very similar requirements.

Guided by the very latest research, based upon precise measurements taken in the natural habitats, a wide-area basking spot that enables the tortoise to raise it's body temperature to circa 30-32 celsius is required, while at night, temperatures can safely fall to circa 5 Celsius. Indeed, wild Mediterranean tortoises routinely experience much lower temperatures than even this. It is a complete myth that they need to be consistently warm. An overnight temperature reduction is normal and desirable for all temperate zone, non-tropical tortoises. It is a part of their normal, natural cycle, and contributes to the correct functioning of their entire metabolism, and of the digestive tract in particular. Depriving them of this diurnal temperature variation contributes to excessive growth and a number of severe consequences for overall health and development. See "Unnaturally High Growth rates in Tortoises: Causes and Consequences" for more on this subject. The basking zone needs to be as large as possible, not merely a small, concentrated 'spot'. We now advise that it should cover an area of at least 5 times the size of the animals plastron.

It is also a total myth that Mediterranean tortoises need to be warm and active every single day. They do not, even during peak activity periods such as early spring, and in the wild they regularly experience some cold, overcast and very rainy days. We have a video showing how wild tortoises deal with heavy rains. This is totally normal. The idea that they need to be 'baked' under heat lamps in consistently warm, dry indoor enclosures or active and feeding daily could not be more wrong. Indeed, this practice is responsible for causing real harm as it results in stress, dehydration and excessive growth rates.

At the same time as the basking zone, they also require cooler, shaded areas to retreat to so that they can voluntarily reduce their body temperature on demand. This area should be an absolute minimum of 8 °C below the maximum temperature in the habitat. An optimum gradient or differential would be in the 10-15 °C range.

• If an adequate basking temperature is not available a tortoise will be unable to digest food normally and will suffer a compromised immune system and stress.

• If an adequate thermal gradient is not available it may fatally overheat, it will suffer stress, and it will be unable to self-regulate its temperature. It will also, as described above, suffer an accelerated metabolism and a damaging rate of growth.

Both of these conditions are a violation of the requirements of the Animal Welfare Act in respect of the need for a) A suitable environment and b) The ability to exhibit normal behaviour patterns.

If you wish to keep a tortoise, and all you can offer is a life indoors, we strongly urge you to reconsider. Tortoises really do need many things that indoor housing methods simply cannot adequately provide. This applies to both enclosed vivaria and to tortoise tables.

These include:

Adequate floor space.

Tortoises need a lot of space - and we really do mean a lot. A typical vivarium as sold by many pet shops for use with tortoises has a total external size 86cm wide, 37cm deep and a height of 42cm. It is often claimed that units like this are "suitable for small to medium tortoises" and offer "excellent ventilation". Both of these claims are misleading and are untrue. A floor area of 86 X 37 cm translates to approximately one third of a square metre, or just under 3 1/2 square feet. That is tiny, and is totally unacceptable. It is barely even adequate for a single hatchling, let alone a "small to medium tortoise". It should be noted that tortoises do not possess a diaphragm and that respiration is dependent upon the serratus, abdominal obliquus, pectoralis and transverus abdominus muscles for inhalation and exhalation. Lack of exercise can result in muscular atrophy and may consequently contribute to the very high incidences of respiratory problems observed in tortoises maintained exclusively in restricted indoor habitats.

Units like this are completely unsuitable as their floor area is so restricted. Tortoises need lots of space!

The real-life natural habitat of the species shown above (Testudo graeca graeca). How can it be right than an animal that lives in wide-open spaces like this should be confined to a tiny tank that provides no exercise, no stimulation and a complete lack of vital environmental factors such as suitable microclimates, ideal temperatures and a perfect combination of broad-spectrum radiation (visible light, UV and infra-red).

Adequate ventilation

As for the claim that typical enclosed vivaria have "excellent ventilation" that is also demonstrably untrue. What they normally mean is that they have included some small ventilation holes.

Typical ventilation grille on a wooden-type enclosed vivarium. In our tests these were completely ineffective.

We tested this claim using several trial vivaria of varying makes and dimensions. We placed a highly sensitive precision air movement meter in several positions within each vivarium. The air movement in every case was so low that we could not even get a reading. The measurement vanes did not move at all (see upcoming video of these tests). This should be compared to the same instrument being used to measure air movements next to live, wild tortoises in their natural habitats where quite high wind velocities are common. This is actually very important as a lack of ventilation is a major contributor to the development of potentially fatal respiratory diseases in tortoises. It also greatly interferes with their ability to thermoregulate adequately.

Adequate levels of overall illumination ('brightness')

We briefly mentioned this above, but outdoors in tortoise habitat it is typically very bright indeed. Levels of 90,000 to 130,000 LUX are common. Indoors, in a typical enclosed vivarium tank levels of less than 1,000 LUX are often seen. This deficiency has profound effects upon behaviour and upon their hormonal cycles.

The need for a stimulating, fulfilling habitat

Very recent research confirms that tortoises do indeed experience moods and mental states not that different from humans or more familiar animals such as dogs (“Evidence of mood states in reptiles” by Tatjana Hoehfurtner, Anna Wilkinson, Sophie A. Moszuti and Oliver H.P. Burman, 28 June 2025, Animal Cognition.). This will not be new to those of us who have observed these animals over many years, both in captivity and in the wild, however as it is perfectly obvious. However, it is certainly something that those who keep tortoises confined in tiny enclosures that offer nothing of the outside world need to consider. We have written about this very subject previously. See our article "Habitat Enrichment for Tortoises - Do we underestimate their real needs?".

To summarise, there is no perfect indoor accommodation for tortoises, but there are certainly some options that are worse than others. We have no hesitation in saying that small glass 'tanks' and wooden enclosed vivaria are the two worst possible choices for tortoises. If that is all you can provide, please reconsider keeping these very sensitive animals in the first place. We realise that this message will be unwelcome to many, but our primary focus is on promoting the welfare of tortoises, and we cannot in good conscience condone keeping these animals in conditions that demonstrably fail to meet their basic physiological and behavioural needs, and which will undoubtedly cause stress and ill-health.

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Copyright 2025 A. C. Highfield/Tortoise Trust