Molting is a cause for concern for many keepers, new and old alike, because the poses a spider adopts during the process can appear alarming. Typically, tarantulas will flip onto their backs to complete the molting process.
This is why the general rule of thumb is that a spider on its back is fine, whereas a spider that has its legs curled underneath it is going into a death curl. However, this doesn’t always hold true.
Tarantulas can molt right side up, although this is an abnormal occurrence. They can successfully complete a molt standing upright and even on their side. A telltale sign that a tarantula is molting is the carapace popping open to allow the spider to wiggle out of its old exoskeleton. The difference between a death curl and a spider that is molting upright is in the position of the legs.
How do you know if a tarantula is molting right side up or dying?
A tarantula that is attempting an upright molt won’t have its legs curled fully underneath it like a dehydrated or dying spider does. They usually begin in a position that appears very similar to the way they naturally sit.
In contrast, a normal molting position starts flipped over on their back with the legs usually held flaccidly outstretched to the side. Once the tarantula has fully pulled itself out of the old exoskeleton, they may rest with their legs curled over their body while still on their back.
Terrestrial specimens often will even forgo putting down a molting mat before starting if they are trying to molt right side up. You can tell that the process has started by looking at the carapace. Popping the old carapace off is the first step of molting, so look to see if it’s lifted open. The tarantula will wiggle out of that opening, very similar to the way we take off a glove from our hands. Once the carapace pops, the abdomen will start to look deflated.
When a tarantula is going into a death curl it will have its legs underneath the body as opposed to a normal sitting stance – think of what your hand looks like when you hold it in a clawed position. How far under the legs are positioned underneath the body will depend on how far they have progressed into a death curl. The end stages are very pronounced, with the legs completely tucked underneath the spider when it dies.
Is something wrong if my tarantula doesn’t molt on its back?
Abnormal molting positions don’t necessarily indicate that something is wrong with the spider, or that anything wrong will happen during the molting process. In fact, arboreal species are known to regularly molt on their sides. Sometimes, an abnormal molting position can indicate that the spider has something wrong with it and it’s forcing a molt, though.
Should I flip my molting tarantula onto its back?
Do not touch a molting tarantula. If you find your tarantula molting upright just leave it alone. Don’t try to intervene by flipping it over onto its back. Most of the time, upright molts turn out just fine.
Allow adults to have a full 24 hours undisturbed to complete the process. Unless there is a glaring problem, like the spider is pulling itself out of the old exoskeleton asymmetrically (all the legs pump out of the old exoskeleton rhythmically at the same time in a normal molt), then you will only end up doing more harm than good.
If a tarantula is really stuck in its molt, then you won’t see visible progress, such as the old carapace popping up. Otherwise, it’s likely that you have just caught your tarantula resting mid-molt.
Should I mist my tarantula with water if it’s molting upright?
Do not directly mist your tarantula while they are in the process of molting. They don’t need humidity for a molt, they need internal hydration and the time to have provided that for them was when they were in premolt with a water dish. Misting a molting tarantula will only startle it, and possibly end up injuring the spider if they attempt to get away.
How long should it take for a tarantula to finish molting?
The time that it takes for a tarantula to free itself from the old exoskeleton will vary depending on the size and age of the specimen. Molting becomes a more precarious endeavor for older tarantulas because the process requires a lot of energy and moisture.
In general, you can usually expect small specimens to finish molting in under an hour. Larger specimens will often take anywhere from one hour all the way up to nearly half a day to successfully complete a molt.
In general, there’s nothing to worry about as long as the molt is completed within 24 hours. Tarantulas will often go through periods of inactivity during a molt as they rest because it’s such a taxing event.
Final Thoughts on Tarantulas Molting Upright
In my experience, molting upright while standing perfectly on all 8 feet doesn’t happen frequently, though it certainly does happen. However, molting in really odd positions, such as wedged up sideways against the glass or a hide is much more common, especially for slings and juveniles. My arboreal tarantulas seem more likely to have odd positioned molts throughout their entire lifespan, whereas most of my terrestrials tend to flip over as expected once they are adults.