Molt Frequency by Age
Spiderlings and young juvenile tarantulas grow quickly and may molt every few weeks to a couple of months, since molting is how they increase in size — their exoskeleton doesn’t stretch. As they mature, molting slows considerably, and a fully grown adult tarantula might molt only once a year, and in some older individuals, even less frequently than that.
Signs a Molt Is Coming
- Refusing food for days to weeks beforehand — this is one of the most reliable early signs
- A darkened, dull-looking abdomen
- Reduced activity or a period of unusual lethargy
- In some species, spinning a silk web mat to molt on top of
What to Do (and Not Do) During a Molt
Don’t handle a tarantula that’s showing pre-molt signs or actively molting — they’re extremely vulnerable during this process, and any disturbance can cause serious injury or a failed molt. Don’t offer food either; a tarantula won’t eat during this period and live prey left in the enclosure can actually injure a molting or freshly-molted spider that can’t yet defend itself.
Post-Molt Recovery
After molting, a tarantula’s new exoskeleton, including its fangs, is soft and needs time to harden — typically several days to about two weeks depending on the species and size. Wait until the fangs have visibly darkened back to their normal color before offering food again.
FAQ
A molting tarantula is usually on its back, which alarms new keepers, but this is the normal molting position. A dead tarantula typically has curled legs and doesn't respond to gentle vibration near the enclosure; a molting one is simply still.
No, wait until the fangs have hardened and darkened, usually several days to two weeks, before offering food again.
Very old adult tarantulas, especially some long-lived females, can molt very infrequently or occasionally appear to stop altogether, though this varies by species and individual.
Occasionally a leg is lost during a difficult molt, but tarantulas can typically regrow a lost limb over subsequent molts, so it's not usually a lasting problem.
