Tarantulas are cold-blooded invertebrates that hail from the warmer parts of the world.
For most of us, therefore, some form of artificial heating will be required to keep your spider in good health.
While it always pays to seek out specific information on the type of tarantula you plan to keep, as a rough guide a temperature of around 24’C tends to work well for most species.
Fortunately, heating tarantula cages is both simple and cheap, thanks to a range of reliable and low-cost alternatives on the market. So let’s get started with choosing and setting up the heating that your tarantula needs…
The Best Heaters for Tarantulas
While big breeders may heat an entire room of their house to a comfortable 20+’C throughout the year, most of us will rely on heating only our tarantula’s cage itself.
Here there are three popular and effective options…
A heat mat can be considered the “standard” among tarantula keepers. Resembling a flat, black piece of plastic, these heaters produce very gentle background warmth.
Even when running at full-pelt, they feel only comfortable to the touch, rather than unpleasantly hot. This makes them quite safe. The low power they produce also makes them cheap to run.
Heat mats come in a wide range of different sizes, depending on the size of your spider’s cage. They are freely available from most specialist reptile shops, and even some traditional pet shops.
It’s always worth checking out prices on sites like Amazon, where the prices can be considerably lower than in some pet stores.
A heat strip can be thought of as a long, thin heat mat. The reason that they have these dimensions is simple; the can then be used to heat a number of invertebrate cages at the same time.
Should you decide to purchase a handful of different tarantulas at the same time (or long to expand your collection in the near future) then a heat strip might just be the answer to your needs.
Lastly, an even more extreme form of heating comes in the form of heating cables.
These are often sold as “soil warming cables”, intended for use by gardeners. Looking like a thick flex of electrical cabling, they can be used to heat dozens of tarantulas, mantids, leaf insects and more all at the same time.
Really only therefore suitable for the hardcore invertebrate keeper, if you have a range of exotic pets then a heating cable can work out to be the most practical and cost-effective way to heat a multitude of different cages.
How to Heat a Tarantula Cage
Tarantulas require what is known as a “thermal gradient”. This is a fancy way of saying that one part of the tarantula tank should be warmer than the other.
Typically one end (or one side) of the cage is heated using a heat mat, while the other is left unheated. This creates a range of different temperatures within the cage. Should your tarantula feel cold, it can then move towards the warmer end. Equally, if they’re getting too hot they can then move towards the cooler end of the cage.
A gradient like this can also be a handy tool for checking that your tarantula’s cage is an appropriate temperature.
For example, if your spider rarely ever seems to leave the warmest part of the cage, then it may pay to raise the temperature a little bit. Equally, if your spider is repeatedly found cowering in the coolest part of the cage then it may be time to reduce the heat overall.
There are two traditional ways to use all the tarantula heaters outlined above. Each is used outside the cage rather than inside. The first method is to place your tarantula tank ontop of the heater, ensuring that only 1/3 to 1/2 of the cage floor is actually heated. The other half is left without heat.
The alternative method is to attach the heater to the side of the cage.
So why are there two ways to fit a heater to a tarantula cage, and which is the best option?
Placing your tarantula tank ontop of the heater was what tarantula keepers of old used to do. It was the “traditional” way to heat a tarantula tank. However, a number of concerns were raised over the years about this method.
Firstly, it can greatly increase the humidity in the cage, pushing it past acceptable limits.
Secondly, as tarantulas normally burrow down to escape the hottest conditions, it might seem odd for your tarantula to find it actually gets hotter the more they burrow down.
Lastly, many tarantula substrates aren’t very good conductors of heat. Placing the heater under a thick layer of substrate therefore reduces the heat getting up to your spider, and can even lead to heaters getting too hot. In extreme circumstances the glass of cages has split before thanks to overheating.
It is therefore understandable that attaching the heater to the side of the cage gained in popularity. It maximizes the heat that can get into the cage, without the risk of overheating.
It creates a more “natural” environment, warming the air rather than just the substrate, and is also ideal for arboreal species that spend very little time at ground level. This is made all the easier by the fact that many heat mats today come with a self-adhesive side. Simply peel off the plastic covering and glue it to the outside wall of the cage.
Thermotstats for Tarantulas
Manufacturers of heat mats generally recommend that even these low-powered heaters should be used in conjunction with a thermostat. Such a device controls the heat provided, ensuring that your tarantula doesn’t overheat in warmer weather, or that any issues with the heater don’t end with a roasted tarantula.
While some keepers still shun the extra cost of buying a thermostat (and thus take risks with their pet) the good news it that thermostats designed to control heat mats are actually quite cheap to buy. This isn’t always the case, as thermostats for more powerful heaters can be surprisingly expensive.
My own personal recommendation is therefore to grab both a heat mat and a matstat together, then sleep easy knowing that you’ve got all eventualities covered, no matter what the weather does.
Thermometers for Tarantulas
Lastly in this article I recommend that you keep a manual eye on the temperature of your tarantula tank on occasion. This is of particular importance when you first set up your tarantula tank, just to make sure that your thermostat is set up and working correctly.
Possibly the most effective option here (and my own preference) is one of the digital thermometers with a heat-sensing probe. This can easily be fitted to most tarantula tanks. Alternatively, dial thermometers may be used, though I have found their accuracy to not be quite as great as their digital equivalents.
So that’s it. Depending on how many tarantulas you’re planning on buying, buy a suitable heater and thermostat. Set them up as described above, monitor the temperature carefully for a day and or two and you should be all ready to go.
Following such a process your tarantula tank should be heated effectively, allowing your pet tarantula to live out a long and healthy life in your care.