Wild Hermit Crabs naturally inhabit warm, humid and tropical environments across Australia. However, fast forward to 2023 and upwards of 30,000 wild Hermit Crabs are captured and sold yearly to pet stores Australia wide.
This means, majority of the wild caught and sold Hermit Crabs are heading to homes in some of the coldest parts of the country.
What does this mean? We, as owners, must now work extra hard to ensure that the home we provide for these crustaceans is kept hot and humid to ensure a healthy lifestyle and a fighting chance at survival in captivity.
But how do we do that, when some of us face some of the coldest winter days and nights for months on end.
Below we will talk about safe ways to ensure your Hermit Crabs are still living their everyday summer, all year round, even in winter.
The optimum temperatures for captive Australian Hermit Crabs should sit between 26-32.c degrees, with 28.c being optimal, with humidity levels that should consistently sit between 70-85%.
Come winter though, that tends to fly right out the window and most of us will hit struggle street trying to keep our temperatures within the safe level.
I know it sounds hard, but not all hope is lost. Try the below ideas to get your tank stats back on track during winter.
Deep Substrate It is not just for molting! Deep sub means less air space, less air space means less air to heat. And that is all you want to heat, the air. Substrate should be at a minimum of 6 inches (15cm) if you have room to go deeper, you should.
Add More Heat Your heat source, whether its heat mats or heat cords, should cover majority of the back of the tank, sitting above the substrate level. Still not enough to get your heat up? It's all about the wattage! Anything below 20W will not make much of a change in your temperatures. The higher the wattage (W) the more heat you will get into your tank. If you still can't get that temp up, add heat sources to the sides of your tank.
INSULATE! One of the most common issues we come across is that owners don't know just how important insulating is. What can you use to insulate your tank? The supplies are easy to find and often quite affordable. You can use insulation mats, car sun shields or polystyrene. All insulation should be placed on the outside of the tank, sitting over the heat source. This is both a safe and affordable option to save your temperature from dropping. Insulating your tank can save up 20% of heat loss!
Blankets I know this may sound scary, but when done right, it really pays off! During those cold winter nights, adding a thick blanket to the top of your tank can raise your temperature by as much as 3.c degrees! Only place your blankets on the top/front of the tank, try to avoid laying them on the heat source, not enough heat will generate out of the lid/front of the tank to create a fire hazard, so this is perfectly safe and a very common practice in the Hermit Crab community. If your temperature dips during the day, add the blankets to the tank during the day too.
Body Warmers/Hot Hands While these are only quick, temporary fixes and can certainly add up in cost, they can be very handy if you are suffering from a cold blast or an electrical blackout. Purchase instant body warmers/hot hands and stick them to the front, sides or top of your tank (on the outside only) and place your blankets over the top. They can add a small amount of heat source back into the tank, which can be helpful when you have no access to electricity.
Hot Water Bottle Method No, we don't mean an actual hot water bottle, that is a disaster waiting to happen! The hot water bottle method is a great quick fix, but temporary solution to low temps or electrical blackouts. Simply boil water, fill a water bottle (make sure this water bottle is heat safe, we recommend stainless steel), cover the boiled water bottle in a towel or cloth and place it directly into the tank. You MUST cover the bottle in a towel or cloth to prevent any burning injuries to crabs. This will generate some heat into the tank and gives your Hermit Crabs the option to huddle up against it if they are feeling cold.
Ultimately, heat and humidity are your most important aspects and should be something you prioritize, if temperatures dip to low, Hermit Crabs will be forced into an unnatural hibernated state. This is their last resort to sustain life, before death occurs. While they can sustain short periods of low temperatures, this is not something they should be experiencing for days, weeks or months on end.
We commonly see owners come forward, worried for their temperatures during winter, they have the entire tank covered in heat sources, everything is insulated etc. yet still, their temperatures are dangerously low!
It does not matter how many heat sources you have or how much insulation you have added, it's all about that wattage! Covering a tank in 7W heat mats will not make a difference in your temperatures and having low sub will only create more air needing to be heated.
We will use our very own tanks as an example of wattages, sizes and our normal winter temperatures.
Wallan, Victoria - Winter Temperatures - averaging between 6 - 11.c degrees during the day, averaging between -2 - 3.c degrees overnight.
Tank 1 - 6-foot Tank, with 1/3 Topper
We have around 185W on our tank/topper (sides and back) each heat source is insulated, and at night we place 2 blankets on the tank. Daily average temps sit between 27-29.c degrees during winter days, winter nights with blankets, it drops to an average of 26-28.c degrees.
Tank 2 - 2-foot Tank We have 40W on our 2-foot tank, one side/back, fully insulated. Daily average temps sit between 28-30.c degrees during winter days, winter nights it drops to an average of 27-28.c degrees. We do not add blankets to this tank as it holds its temperatures well on its own.
Come Summer, you can remove your winter heat sources if needed, we recommend starting by removing your side heat and insulation until you get your summer temperatures where they need to be. You can overheat your Hermit Crabs, so it is important that your temperatures are something that you are monitoring daily.