As tarantulas grow, they regularly shed their exoskeletons in a process called “molting.” Molting happens at regular intervals throughout a tarantula’s lifecycle, occurring with great frequency when the tarantula is a sling and a juvenile, then with less frequency – but still regularly – when the tarantula reaches mature adulthood.
Why Is Your Tarantula Molting?
Put simply, your tarantula is molting because it’s growing.
As with most arthropods, tarantulas’ bodies are protected by an exoskeleton. However, this exoskeleton doesn’t grow with the tarantula the way our bones grow with us.
Tarantula exoskeletons are made of a chitinous fiber that is both rigid and flexible, offering the T maximum protection while allowing for full range of motion. It’s like custom made body armor that needs to be replaced regularly.
Molting allows the tarantula to upgrade its body armor while also expanding in size. A new, better fitting exoskeleton replaces the old one after each molting.
How Often Will You See Your Tarantula Molting?
The frequency of a tarantula’s molting depends on the age and species of the tarantula itself.
Generally speaking, young tarantulas grow very rapidly. Because of their rapid growth rate, they tend to molt quite frequently. On average, sling and juvenile tarantulas molt once per month, but the frequency of the tarantula molting declines as it matures.
Adult tarantulas may continue to grow, but at a much slower rate than slings and juveniles. Because of this, they don’t need to shed their exoskeleton as frequently. For them, molting is more like armor upgrades than a total refitting. Most adult tarantulas molt once per year.
The frequency with which your specific tarantula sheds its exoskeleton depends on what species of tarantula you’re keeping. Some species mature much more slowly than others. As a rule of thumb, the longer the average lifespan of the tarantula, the slower the growth rate.
How Long Does It Take a Tarantula to Molt?
As with the frequency of molting, how much time it takes a tarantula to molt depends on age.
Younger Ts tend to shed much more quickly than older Ts. It’s not uncommon for a sling or juvenile to complete its molting in around 15 minutes. Adult tarantulas, on the other hand, can take much longer. Some adult tarantulas take up to 24 hours to complete a molting.
But even after your tarantula has finished shedding its exoskeleton, it’s not quite done with the molting process. It takes several days to just over a week for your tarantula’s new exoskeleton to harden. During this time, your tarantula will be very vulnerable and sensitive, and you should refrain from feeding it as any live insects – particularly crickets – can injure or even kill your T during this time.
Pro Tip: Do not attempt to handle your tarantula while it’s molting. Your T is stressed enough and is focusing all of its energy and attention on getting out of its old exoskeleton. Not only will handling your tarantula add to its stress, but you also risk injuring it.
How to Tell if Your Tarantula is Molting: 7 Signs to Look For
“Is my tarantula dead?”
This is a common question among new T-keepers the first time they encounter their tarantula laying on its back or side.
But if you encounter your tarantula laying on its back, you have nothing to fear. Tarantulas lay on either their back or their side when they’re about to begin the molting process. A dead tarantula, on the other hand, will be face down with its legs curled under it.
Other signs that your tarantula is about to begin molting include:
- A drop in appetite
- Lethargic behavior
- A shiny bald spot develops on its abdomen
- A dulling of its colors
- Your tarantula builds a molting mat
- Your tarantula spends more time in hiding
If you notice any of these signs, the best thing you can do for your tarantula is to make sure the temperature and humidity levels are just right for its particular species. Also be sure to remove all uneaten feeder insects as they can harm or even kill your tarantula during this vulnerable time. Then just step back and let your T do its thing.
Takeaway: Like most other arthropods, tarantulas need to shed their exoskeleton as they grow. Younger tarantulas, on average, molt once per month, whereas adult tarantulas typically only molt once per year. A tarantula’s molting process can take anywhere from 15 minutes to 24 hours, and they usually need an additional week or so of recovery so that their new exoskeleton can harden.
