Terrarium Heating

As cold-blooded animals, reptiles and amphibians cannot regulate their body temperatures internally. Instead, their body temperatures are determined by their external environment.

In nature, these animals often warm themselves by basking in sunlight or absorbing heat from the surface of a rock. They cool off by moving into a shaded area or soaking in water.

General Heating Guidelines

1. Reptiles and amphibians should be exposed to different gradients of heat, instead of a single temperature throughout the entire terrarium. To create variations of temperature, the heat source should be positioned at one end of the tank rather than in the middle. This allows the animal to cool off by moving away from the heat source.

2. Have "water pools" and shaded spots to provide herptiles with cool off areas in the terrarium.

3. Focus light on rocks to create "basking areas" where herptiles can raise their body temperature.

4. Position heat source so it cannot come into direct contact with animals.

5. Providing reptiles and amphibians with adequate heat aids the digestion process, and improves the immune system.

6. All terrariums should have a high-range thermometer that can reads temperatures in the upper 90s and 100s°F.

There are different kinds of heating products available:

Aquarium Heaters
Terrariums that have large areas of water and require high humidity can be heated by an aquarium heater. Placing a thermostat-controlled aquarium heater in a terrarium "pool" will not only raise the water temperature, it will also keep the air in the tank warm and humid. (For more information see the "Aquarium Equipment -- Heaters.") In most terrariums, water temperature should be set in the upper 70°s (Fahrenheit).

Area Heaters
Area heaters can be used to maintain a minimum "base temperature" throughout the entire terrarium. Do not use an area heater to warm the terrarium to its highest temperature. Using an area heater for this purpose will not provide the gradients of temperature within the terrarium that reptiles and amphibians need. For best results, use an area heater in combination with spot heating units.

Heat Rocks
Although very popular, heat rocks should not be the only source of heat in a terrarium. Heat rocks will not distribute enough heat throughout the terrarium, especially if it houses an arboreal (tree-climbing) reptile. When the arboreal reptile climbs up branches, the animal will be out of the rock’s heated region. An area heater or other supplemental heat source should be used with a heat rock.

Be careful not to allow heat rocks to burn reptiles’ skin. Covering heat rocks with sand, gravel or slate will help protect reptiles. Heat rocks should be mounted on pegs to raise them off the floor. If a reptile begins to shed excessively, it may be due to the heat rock generating too much heat. Some models of heat rocks can be controlled by a rheostat to prevent them from over-heating.

Heating Pads, Tapes & Cables
Placed under the terrarium floor, heating pads, heating tapes or heating cables can provide a dependable heat source for non-tree-dwelling animals. In order to provide the necessary gradients of temperature, heating pads and tapes should be placed only under one-third of the tank floor. This will create a good mix of hotter and cooler floor areas in the terrarium.

Incandescent Heat Lamps
Incandescent lamps or tungsten light bulbs (ordinary household light bulbs) that have been specially treated for terrarium use are another popular heating option. Some terrarium incandescent bulbs contain an element called neodymium, which acts as a filter to prevent the light from becoming too hot for reptiles.

An advantage of incandescent lamps is that they can be used to create specific basking areas in the terrarium. For example, a bulb can be directed upward to create a hot area in the branches above the tank floor for arboreal animals.

Spot Heating Lights
Spot lamps direct a focused beam of light and heat at a specific spot in the terrarium. Often used with other heating sources, they create areas of high temperatures for basking. Because the spotlight is concentrated on a relatively small area, the reptile can move away to lower its body temperature.

Infrared Lamps
Unlike "convective" heat sources such as heat rocks and incandescent lamps, which transmit heat by warming the environment, infrared heat sources heat objects directly by emitting electromagnetic waves. When these waves come into contact with an object, they produce heat by activating electrons in the object itself. Because it warms the object directly, infrared heat is largely unaffected by drafts. In addition to providing heat, infrared lamps can be beneficial for animals with rheumatic conditions, sore muscles and stiff joints.

Ceramic Emitters
Some infrared lamps are equipped with opaque ceramic bulbs called ceramic emitters. These bulbs will produce infrared heat, but no light. The advantage of ceramic infrared emitters is that they can be used night and day without disturbing the animal's sleep pattern because they will heat a darkened tank without illuminating it.

Infrared Panels
One of the newer heating options, infrared radiant heating panels resemble ordinary acoustic ceiling panels. They have relatively low surface temperatures and can be mounted directly on top of a cage or enclosure. They operate on the same infrared heating principles as infrared lamps. There are also heating panels that fit to the side of a tank that the animal can move toward, or away from, to raise or lower its body temperature.

All terrarium heaters (convective and infrared) should be controlled by a thermostat to prevent over-heating. The thermostat should be positioned well away from any basking area, so it will get an accurate reading. Connecting heaters to a "rheostat" will automatically shut them off when they start to over-heat.