6 Ways to Warm Up Your Vivarium in Winter

As winter approaches, and the temperature drops, its not uncommon for that formerly toasty reptile cage to start developing quite a chill.

The heater that has done its job perfectly for months on end finally starts to struggle to deal with the cold. All too soon, if you’re not careful, the cage temperature drops dangerously low, and action needs to be taken.

The Problem with Heat Mats

Most invertebrate keepers, and even many snake owners, use low-wattage heat mats to warm their vivariums. While these are a safe, low-cost and generally effective way of providing artificial heat, they’re not without their weaknesses. The main problem being that they only produce a gentle warmth.

While your reptile cage may sit comfortably at 25’C during September and October, by the time winter sets in properly its not uncommon to find the ambient temperature in the cage dropping. This is especially so if you’re out at work or school during the day, as it’s unlikely you’ll have your household heating on to take the edge off things.

So what can be done?

basking photo

Over the years I’ve lived in some very cold properties – more than one of which didn’t even have central heating. In that time I’ve had to test and develop a range of techniques for significantly increasing the temperature in my vivariums, especially those with plenty of ventilation which can let the cold air in.

Here are my tips for keeping your vivarium warmer, if your current heater isn’t doing it’s job effectively enough…

Upgrade Your Vivarium Heater

If your reptile heat mat isn’t raising the tank temperature up enough then the first obvious solution is to invest in a more powerful heater. The obvious question then becomes – what’s more powerful than a heat mat?

Putting aside most lizards for a moment – who should have a high-powered basking lamp at all times anyway – what we really need is a source of underfloor heating for your tarantulas, mantids or snakes. This can then be used just as your heat mat is right now, but simply gives out rather more warmth.

In the 20-odd years I’ve been keeping reptiles and invertebrates I’ve experimented with a range of options, but possibly the most effective has been soil-warming cables.

reptile photo

These are long, waterproof wires, designed for greenhouse gardeners. The theory is that these cables can be buried in the earth of your beds, thus gently warming the soil. This encourages quicker germination and more vigorous growth.

But the same piece of equipment can be used quite effectively in the home by reptile keepers.

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The heaters come in a range of different lengths, so you can choose an option which suits the number of cages you have to heat. The cable can then be run along behind or under each of your reptile cages.

I have found that these provide considerably more heat than heat mats, so are an ideal solution for cold winters. Personally I use tape like this to fix the cable down, otherwise every time you move your vivariums you’ll disturb the cabling.

IMPORTANT NOTE: As soil warming cables can get very warm (I’ve heated ball pythons to 30’C using them without issue) it is essential that they are used with a suitable thermostat. This ensures that your precious reptiles won’t overheat, even if the ambient temperature in the room starts to rise.

Add a Second Heater

Just because your heat mat isn’t quite getting the temperature high enough doesn’t necessarily mean that you need to replace it altogether. A second option is to add a second source of heating to the mix.

This is often the solution I use with my Exo Terra terrariums, which with their all-glass construction and well-ventilated lids, don’t hold the heat as well as a wooden vivarium might.

In the case of my Exo Terras I use the special tank lids that can be purchased separately, and place a low-powered heat bulb like this one into it. I find a 25W bulb is more than effective even in the coldest weather.

reptile photo

This heat bulb is then controlled in two manners. Firstly, it is placed on a timer, so I don’t need to remember to turn it on. Most of mine are scheduled to be on between 10am and 6pm. Secondly, as with soil warming cables, be sure to use an effective thermostat to control the vivarium temperature.

Combining my hat mats with heating lamps allows me to produce almost any temperature that my reptiles need with the minimum of fuss each winter.

Use a Reflector

Hat mats give out warmth from both sides – even though only one is placed next to the vivarium. In many cases, therefore, you’ll find that you’re heating the shelf or table that the tank is on as effectively as the vivarium itself.

Using a reflector behind or underneath the heat mat can therefore help to reflect more of this beneficial heat into your vivarium.

I use two different options here and have found them equally effective. On the one had I use polystyrene tiles for under-tank heaters. I just place down a few tiles, put the heater ontop, and then place the vivarium over this.

For heaters attached to the sides of vivariums I’ve had excellent results with self-adhesive cork tiles, which are just as insulative but look visibly more attractive stuck to the side of the tank.

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Insulate Your Vivarium

While wooden vivariums tend to retain their heat well (and so I my general recommendation for most reptiles), invertebrate keepers using glass or plastic containers may struggle a little more.

We’ve already discussed the possibility of using cork or polystyrene as a reflector, but these can also be used to better-insulate cages.

reptile photo

I know of several keepers who use a hot glue gun to attach cork tiles to the outside walls of their glass tanks, leaving just the front area free of insulation. They report that this process can be very effective indeed for keeping in heat during the winter, and so keeping the cage warmer than before.

Reduce Ventilation

Ventilation is a touchy subject among exotic pet keepers. After all, everyone knows that ventilation is important to prevent mould build-up, but can reducing this ventilation in a reptile cage help to boost it’s temperature?

I would argue almost certainly that the answer is “yes”. For example, if you’re using an Exo Terra with a mesh grill lid, then popping one or two of the tank covers on, or adding a piece of clear plastic over part of the lid can be a highly effective way to increase the temperature in the cage.

If you’re going to down this route, however, be sure to keep a closer eye on the cage than normal, and never block off all ventilation.

Heat the Room

The last option, as used by some serious reptile keepers, is to heat not just your reptile vivariums, but also the room that they’re placed in. Some people, for example, will keep the door to their “reptile room” closed, and leave an oil-filled radiator or suchlike on low power throughout the day.

The radiator doesn’t need to be on full blast – just enough to raise the ambient room temperature to some 16-20’C is normally more than enough to let your heat mat do the rest of the job.

reptile photo

Whichever option you select, it’s very important that you take action as quickly as possible. A tarantula, mantis or snake that is kept far too cold for too long is at risk of developing health issues and/or going off food. In extreme situations the impact could even be fatal.

If you’ve noticed that your pet seems sluggish, or that your thermometer is reporting a far lower vivarium temperature than you would like, it is wise to get any necessary equipment ordered now so that you can resolve the issue as soon as possible.

Photos c/o highlander411 & © Axel Naud


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