How to heat up a terrarium?

Almost all of the animals that we keep in a terrarium are said to be ectothermic.

That is to say that their body temperature is strictly dependent on the temperature of their environment.

Thus in a terrarium, as in nature, the animal carries out behavioral thermoregulation.

That is to say that the animal will be placed alternately in a hot zone or a zone cooler to keep your body at an ideal temperature during the day and according to its needs.

For each species, we speak of “preferred mean temperature” (TMP), which is the temperature at which the animal’s biological functions are performed optimally.

When its body is at a temperature below its TMP, the animal will move to the hot zone and vice versa if its temperature is higher than its TMP.

In terrariums, it is therefore essential to recreate a thermal gradient so that the animal can thermoregulate itself correctly.

Thus the heating elements must be placed to recreate a hot zone slightly higher than the TMP of the species and a cold spot lower than this one.

Suppose heating can be provided during the day only by the lighting elements (if the size of the terrarium and the requirements of the animal allow it) at night.

In that case, it is necessary to use a heating system that does not emit light to respect the animal’s day/night rhythm.

Ideally, it is, therefore, suitable to separate the lighting system from the heating system.

Generally speaking, the heating elements which do not emit light are heating cables, heating mats, and ceramic lamps.

For safety reasons, we must avoid putting these elements in the terrarium to prevent (1) that the material is degraded and (2) that the animal does not injure itself.

The heating cord

Ideally, it will be placed under the terrarium.

CAUTION: the heating cord must not come into contact with the glass of the terrarium.

Indeed, the significant and very localized heat given off by the heating cord can cause the glass to shatter.

The terrarium must be raised so that the bottom of the terrarium and the heating cord is at least 5mm apart.

Likewise, the heating cord must not be crossed to avoid overheating points.

The thermal gradient of the terrarium is carried out by snaking the cord under the terrarium more or less tightly, as shown in the following diagram:

The heating mat

Unlike heating cords, the mat emits more diffused heat and can be placed in direct contact with the glass but always preferably outside the terrarium.

The mat can be glued under the terrarium or on a side face.
Placed under the terrarium, the mat should cover about 1/3 of the floor surface at most to create a warm area.

The ceramic lamp

This lamp, which emits significant heat, will be fixed on supports or reflectors fitted with a ceramic socket.

Even more than with cords or rugs, ceramic lamps must not be accessible to the animal because the risk of burns is significant, especially for snakes searching for the heat that can wrap themselves around.

To achieve a thermal gradient, the ceramic lamp must be placed above the terrarium at one end.

Indeed, these lamps, often of high power (generally greater than 80W), emit a lot of heat (like incandescent bulbs), increasing the convection movements of the air.

The scorching air near the lamp, less dense, will come out of the terrarium, bringing the air’s humidity.

To limit this phenomenon, avoid using a heating element that is too powerful for the terrarium volume.

To avoid overheating, which can cause material problems and be harmful to the animal, the temperature of the hot zone of the terrarium should systematically be regulated by a thermostat controlling the heating elements’ starting.

The thermostat is also handy for performing a controlled nighttime temperature drop for species that require it.


We often hear that ceramic lamps dry up the atmosphere.

The control of the temperature of the day and the night is a vital parameter for our animals, which must therefore be the object of great attention.

This system must be set up and controlled well before the arrival of the animal in its terrarium and must be adapted to the biological and ecological requirements specific to the species, involving a preliminary bibliographic research.