• Thermostats
  • Lamps
  • Incubation


Whether you are housing a snake, turtle, iguana or any other reptile that requires a heat source in its terrarium, it is very likely that the use of a thermostat is essential to ensure controlled, constant temperatures and a correct set-up. But how do thermostats work, and which one is best suited for our use?

What is a thermostat and what is it used for?

A thermostat is a control instrument that allows us to maintain a constant temperature in a system: we connect our heater to it, such as a heating mat or a heating cable, a lamp, a radiant panel, and it is the thermostat that is connected to the electricity supply. The thermostats used in terraristics are equipped with a probe which is positioned in the area which we want to keep at a constant temperature. Thanks to this, the thermostat will constantly sample the temperature and, generally speaking, will only switch on the heater when it is needed, thus avoiding unnecessary consumption of electricity. But not all thermostats are suitable for use with all heaters, and we will find out why later on.

A number of more or less famous brands have designed and launched thermostats for keeping animals in terraria. Until some time ago, we only talked about analogue thermostats: these are the classic ones, still current and very much in use, with a small knob that you simply turn until you point the indicator at the degrees you wish to keep constant.

Digital thermostats for terrariums and racks

For some time now, digital thermostats have also been appearing on the terrarium market, usually with a backlit screen. With the advent of digital technology, manufacturers have succeeded in incorporating various additional functions into the thermostats, some of which are very useful: the possibility, for example, of setting different clocks and temperatures for the day and night (without having to use a timer or a separate sensor - the only "trick" used with analogue thermostats) so as to reproduce the daily temperature changes that normally occur in nature. This innovation is essential both for those species that need to follow a 'cycling' period during the mating phase, which involves lowering general temperatures accompanied by a further drop in night-time temperatures, and for the incubation of certain eggs that should follow the night-time drop in temperatures.

Other innovations included in some commercially available digital thermostats include an alarm to warn of any problems with the heaters, the temperature always shown on the screen (analogue thermostats do not have a display, so a separate thermometer must be used to keep an eye on temperatures), and even, in the most complete and advanced thermostats, the possibility of using the thermostat in an "inverted" manner for cooling (by connecting a chiller or fans, for example). Some digital reptile thermostats also function as hygrostats: they detect and control the humidity in the environment with the aid of a separate, dedicated socket to which a vaporizer, fan or dehumidifier can be connected, depending on the intended use.
Every heater has its own thermostat!

But not every thermostat can be used for every kind of heater. What does this mean and why? We will try to explain this in simple terms (we don't want to upset the experts!).

Thermostats can have different 'mechanisms' or modes of operation.


Most on/off thermostats belong to the category of thermostats and are generally the cheapest thermostats on the market. Their mode of operation is very simple: the connected heat source is switched on when necessary, at maximum power, and then switched off once the probe has detected that the desired temperature has been reached. This type of thermostat manages to maintain an accuracy range of about a couple of degrees. For example, if we are interested in obtaining 28°C at the point where we place the probe, our temperatures will most likely vary between 27°C and 29°C.

The following can be connected to this type of thermostat: heating mats, heating cables, radiant panels, ceramic lamps, infrared lamps - in general, all sources of heat that are NOT bright (imagine a bright lamp connected to such a thermostat: it would be continually switched on and off, electrocuting itself in record time and totally disrupting your animals' perception of light)!


Pulse thermostats work somewhat differently from ON/OFF thermostats. Like ON/OFF thermostats, they activate the connected heaters to their maximum output but they do not stay on continuously and constantly. Instead, they transmit 'pulses' of current to the heater which can be longer or shorter and spaced out depending on how close the temperature is to the set temperature. When the temperature and the heater have stabilised, an accuracy range of about one degree or less will be achieved. For example, if we are interested in getting 28°C at the point where we place the probe, our temperatures will remain around 27.5-28.5°C. Because of its accuracy, the pulse mode is preferred by most breeders, and pulse thermostats are also often chosen for reptile egg incubators, where maintaining constant temperatures is of paramount importance.

The following can be connected to this type of thermostat: heating mats, heating cables, radiant panels, ceramic lamps, infrared lamps - in general, all sources of heat that are NOT bright (imagine a bright lamp connected to a pulse thermostat: it would be continually switched on and off with a "strobe" effect, electrocuting itself in record time and totally disrupting your animals' circadian rhythm and perception of light)!


Dimming thermostats differ totally from ON/OFF and pulse thermostats in that their method of operation allows them to regulate the power of the connected heaters, thereby "dimming" the heat expressed. It goes without saying that such a thermostat is able to maintain the temperature with extreme precision, in a range of only a few tenths of a degree. For example, if we are interested in obtaining 28°C at the point where we place the probe, our temperatures will probably remain around 27.8-28.2°C. Thanks to the dimmer, thermostats that work in this mode are the only ones able to control the heat emitted by the lamps (halogen or incandescent) by adjusting their brightness - without turning them on and off completely. They are therefore perfect for use with spot lamps. Some dimming thermostats require the connected heater to meet a minimum wattage in order to function properly (typically 40W for Habistat analogue thermostats).

The following can be connected to this type of thermostat: heating mats, heating cables, radiant panels, ceramic lamps, halogen and incandescent lamps. The following lamps can generally NOT be dimmed and thermostated: lamps that also emit UVB (Solar Raptor Mercury Vapour, HDI and other brands), infrared lamps.


Sunlight with its light spectrum is a fundamental and essential element for the life of many reptile species, and not only. This is why, in captivity, the breeder has to provide for their heat needs (infrared rays), but also for UVA and UVB rays just as they would in nature. On the market there are different types of lamps that emit UVA and UVB rays, which are not the same and are more or less suitable for different species. So how can we be sure that we are making the right purchase?

Just by studying the habits of reptiles in their natural habitat you can get an idea of their requirements for sunlight - and with the help of dedicated breeding sheets you can equip their housing accordingly. It will go without saying that, for instance, species of snakes with crepuscular/night-time habits - such as Pantherophis guttatus, Python regius, Boa constrictor, are not used to basking in the sunlight, preferring to stay hidden during the day avoiding predators. For these and similar species, warmth is essential but UVA/UVB does not seem to be. Nevertheless, some people recommend, and we feel to do so in our turn, to provide a lamp with low UVA/UVB emissions also to nocturnal animals - emissions that must always be appropriate to the range of the species being kept, furnishing the terrarium in such a way that there are dens and shaded areas in which the animal can, if it wishes, shelter exactly as it does in nature.

For other reptile species, however, such as tortoises and lizards (but not only!), UVB rays are very important: they play a key role in the synthesis of vitamin D3, together with heat (which must be present at the same time!). Even for Trachemys scripta, the most common water turtle, UVB is essential! (Source: Todd Pusser)

There are various lamps on the market that provide UVA/UVB radiation:
  • Classic fluorescent "neon" lamps, linear or compact, which do not emit heat and are used "in pairs" with classic incandescent "spot" lamps. They are suitable for species whose natural habitat is generally not in full sunlight (e.g. tree branches or woods) or, in any case, for all those terraria which, due to their size, would not allow the use of "complete" lamps that emit heat, UVA and UVB at the same time, such as the Solar Raptor. Their emissions start to decrease around 6 months of use, after which they need to be replaced (in brands like Arcadia the optimal emissions last up to 9 months of use!).
  • Complete' lamps, such as HID metal halide or MVL mercury vapour lamps from Solar Raptor, which emit heat, UVA and UVB simultaneously. These lamps have the advantage of emitting large amounts of UV- but cannot be thermostatted, so they should be used in appropriately sized terrariums and rooms and the wattage should be carefully chosen. They should be replaced after one year of use. Solar Raptor metal halide and mercury vapour lamps have the best UV-emission.

It must always be remembered that:
  • The UVB percentage emissions must be adapted to the habits of the species being kept - if you are dealing with animals that generally bask in the tropics in the early hours of the morning, you will need a much lower UVB percentage than for desert animals basking in full sun.
  • The basking spot should be large enough to contain the ENTIRE body of the animal. When keeping very large animals, such as Iguanas sp., large tortoises, Tupinambis sp. it is advisable to place several lamps side by side in order to "enlarge" the basking spot.
  • In any terrarium, regardless of the species, it is always necessary to insert shaded areas and dens so that the animal can choose whether to stay in direct light, in the shade, or in any case the thermal gradient in which to stay.
  • The lamps should be positioned HIGH, above the animal's head and never to the side, to avoid damage to the eyes (and to the lamps themselves).

    On our website you will find a wide range of UVB lamps, ready to ship!


The end of winter and the beginning of spring are undoubtedly among the most eagerly awaited periods of the year for all those who are interested in breeding oviparous species: among the most popular are snakes, geckos, saurians, tortoises and chameleons. So whether this is your first experience or you are already an expert in the subject, if you have mated animals and are waiting for eggs that will be incubated at a certain temperature, you should know that you can build your own incubator very easily and quickly (and, above all, without spending too much money!), obtaining a result as precise as (and more, in some cases!) that which you would have using a professional incubator. In this article on the HerpItalia blog we will explain step by step what you need and what to focus on in order to build an excellent home-made incubator.
We also consider that breeders often need to incubate eggs of different species, which therefore require different incubation parameters and temperatures. Relying on professional incubators in this case would require a considerable amount of money. Everything you use to build your simple home-made reptile egg incubator, on the other hand, can easily be reused for the rest of the year for your animals!
A professional incubator has three fundamental characteristics that you will reproduce in your home-made incubator:

  • it is insulated
  • it has an integrated heater that switches on when needed
  • it is equipped with a thermostat that ensures that the temperature is as constant as possible.

How do we make sure that our reptile egg incubator maintains the temperature?

The "container" that will make up our incubator, requiring excellent insulation, will be quite simply a polystyrene box. There are various types, thicknesses and densities on the market: always choose those with a higher density, as they are able to maintain the internal temperature more accurately and for longer. It is also good to recycle the polystyrene boxes you find around and which are used for food and medicines, always paying attention to the thickness! We recommend that you use large boxes, even if you only need to incubate a few eggs: it will be more difficult to have significant temperature changes.

How do we heat our homemade incubator?

The most appropriate heater for an incubator, in our experience, is the heating mat. We much prefer them to heating mats for several reasons: ease of positioning (the adhesive ones are practically ready-made!) and because, by heating with infrared, they do not dry out the air too much and it is more difficult for the environment to overheat. Heating cables can be just as good, but they are a bit trickier to position (loops that are too close together risk overheating and melting the polystyrene) and you have to be careful to use just enough of them to get the degrees you want. Whatever your choice, however, remember this fundamental step: the wattage of your heater must be high enough to reach the target temperature but, if you try to connect it directly to the mains without a thermostat (and thus allow it to express its full power) it should not exceed the target by much!

This important detail is the result of experience, which unfortunately is not always positive: by following the advice, you will have more time to notice if something goes wrong (for example, if the thermostat goes down for some reason or there is a power cut! ) or to correct some distracting mistake (such as leaving the incubator open for too long while you inspect the eggs: the thermostat detects that the temperature has dropped and will turn on the heater at full power and closing the lid after a while could mean that the temperature is well above our target, and for a long time!)

How do we position the heater in the incubator correctly?

It is important to bear in mind that a high-density polystyrene box will keep an almost uniform temperature inside and throughout, regardless of where you place the mat. Obviously, the basic rule for this constant condition is to open the incubator as little as possible, using control thermometers with a probe that allow us to always know inside how everything is going without having to open the lid every time. If you want to try your hand at DIY, you can cut out the central part of the polystyrene lid and close it with a sheet of plexiglass: in this way you will be able to see inside your incubator at all times without having to open it. By attaching the mat to one of the side walls of the box, you will perhaps have a few tenths of a degree more in the egg containers closest to it but, by positioning the thermostat probe near there, you will always be sure that it will not be high in any case.

And the containers further away? No harm done, a few tenths of a degree less is no problem (better less than more!). If you have the opportunity, you can also modify the inside of the box by adding shelves to your incubator that are raised from the bottom to make the most of the available volume: in this case, you can also place the mat on the base. In any case, as mentioned above, where you place the mat is not important as long as the thermostat probe is always in the container closest to it.

Which thermostat is best for a home-made incubator?

Over the years of breeding we have used almost every model of thermostat on the market, both for regulating the temperature of terrariums and incubators. The sensitivity of the thermostat in an incubator is obviously an essential parameter of choice, even more important than a thermostat used in a terrarium. What we recommend is to evaluate the robustness of the eggs that you will incubate: P.guttatus, E.macularius, P.vitticeps, T.Hermanni, are certainly more resistant (accepting a slightly wider temperature range), so an on/off thermostat is already sensitive enough for their incubator. It should be borne in mind, as mentioned above, that the polystyrene box will play a fundamental role in maintaining the temperature and the thermostat will be greatly facilitated in its task. If you want the best possible accuracy and the smallest possible deviation from the target temperature, choose a digital dimming thermostat (analogue ones require a minimum heater of 40w and you will use much less!) or a pulse thermostat.

As already mentioned, place the thermostat probe in the egg container closest to the mat (hint: in some cases we have dedicated a container containing only the incubation substrate, without eggs, to the probe, so as to be sure never to open it and avoid forgetting to place it correctly after inspection).

Why do we recommend placing the probe in a container and not outside in the incubator? The incubation containers in which you will place the eggs are themselves an isolated environment (often without any holes) in which, thanks to the high humidity, the temperature varies somewhat from that of the air in the polystyrene box. With experience you will get to know your homemade incubator to understand how much deviation you have in the box compared to the containers and you will be able to set the thermostat correctly by leaving the probe loose inside. For the first few times, it is best to be as careful and precise as possible.

In several years of keeping snakes, geckos and tortoises, our simple home-made incubators have never failed to meet expectations. Of course, the fact that the eggs do not have to be turned (as is the case with birds!) and that the ideal and basic conditions have to be recreated in the container with the substrate (or water, if incubating in suspension) in which you place them, makes the game much easier!
All that remains is to wish you the best of luck.