Tarantula Molting: Signs, Process & Care Guide [2026]

What Is Molting?

Molting (ecdysis) is the process by which a tarantula sheds its old exoskeleton to grow. Unlike mammals, tarantulas have a rigid outer shell that cannot stretch, so they must periodically break out of the old one and expand into a new, larger exoskeleton underneath.

Molting is one of the most stressful and vulnerable periods in a tarantula's life. Understanding the process helps you provide the right care and avoid dangerous mistakes.

Pre-Molt Signs

Not every tarantula displays all of these signs, but watch for combinations of the following:

• Refusing food — the most reliable indicator; may last days to months in large adults
• Darkening bald spot — the bare patch on the abdomen turns noticeably darker as the new exoskeleton forms beneath
• Lethargy — spending more time hiding and moving less than usual
• Dull or faded coloring — the old exoskeleton loses its vibrancy
• Web mat — many species lay a silk mat on the substrate to molt onto
• Shrunken abdomen — the abdomen may appear slightly wrinkled
• Blocked-off burrow — burrowing species often seal their hide entrance

If you notice these signs, stop feeding immediately. Uneaten prey items can injure or kill a molting tarantula.

The Molting Process

1. The tarantula flips onto its back (this is normal — do not flip it upright)
2. The old exoskeleton splits along the sides of the carapace
3. The tarantula slowly pushes out of the old shell, pulling each leg free
4. The process takes roughly 1-12 hours depending on size
5. After emerging, the tarantula may remain motionless for hours while the new exoskeleton begins to set

Critical rule: Do not touch, move, or disturb your tarantula during a molt. Any interference can cause injury or death.

Molt Frequency by Age

Male tarantulas reach a "terminal molt" at maturity, after which they do not molt again. This is one reason males have significantly shorter lifespans.

Post-Molt Care

The days after a molt are critical. Follow these rules:

• No feeding for 7-14 days — fangs need roughly a week to harden enough to pierce prey; the exoskeleton needs time to toughen
• No handling — the soft exoskeleton bruises easily and the abdomen can rupture from even a short fall
• Provide fresh water — tarantulas are often dehydrated after molting; ensure the water dish is full and accessible
• Maintain humidity — slightly higher humidity helps the new exoskeleton set properly
• Remove uneaten prey — any live insects left in the enclosure can bite and injure the vulnerable tarantula
• Leave the molt — the discarded exoskeleton (exuvium) can be removed once the tarantula has moved away from it; some keepers use it to sex their tarantula

Stuck Molt (Dysecdysis)

A stuck molt occurs when part of the old exoskeleton fails to separate cleanly. Causes include low humidity, dehydration, and mite infestations.

Signs of a stuck molt

• Old exoskeleton visibly attached after the tarantula has righted itself
• Legs appear curled or trapped in old skin
• Tarantula is struggling for an extended period with no progress

What to do

1. Raise humidity by misting one side of the enclosure lightly or dampening the substrate
2. Place a shallow dish of room-temperature water near the tarantula
3. If old skin remains stuck after 24 hours, carefully apply a drop of water with a soft paintbrush to the stuck area
4. Never pull exoskeleton pieces off — this can tear the new skin and cause fatal bleeding
5. If the situation worsens, consult an exotic vet or experienced keeper

Prevention is the best strategy: maintain proper enclosure humidity and always provide a clean water dish.

Common Molting Myths

• "My tarantula is dying — it flipped over!" — Flipping onto the back is the normal molting position. Leave it alone.
• "I should help it out of the old skin." — Never intervene unless there is a clear stuck molt lasting over 24 hours.
• "It hasn't eaten in two months — something is wrong." — Large tarantulas can fast for months before a molt. This is normal.

Related Guides

• Tarantula Care Guide — complete care overview
• Tarantula Feeding Guide — diet and feeding schedule
• Tarantula Enclosure Setup — habitat and humidity
• Best Pet Tarantulas — species recommendations