Premolt vs Postmolt

Understanding the Two Most Important Stages of the Molting Cycle

One of the first skills every jumping spider keeper should learn is recognizing the difference between premolt and postmolt.

Both stages involve significant behavioral changes, and both are completely normal parts of a spider's development. However, they require different care considerations and often cause confusion for new keepers.

A spider preparing to molt may appear withdrawn, refuse food, and spend days hidden inside a hammock. A spider recovering from a molt may display many of the same behaviors.

Knowing the difference can help you avoid unnecessary stress, overfeeding, and accidental disturbances during one of the most vulnerable periods of your spider's life.

What Is Premolt?

Premolt

Premolt is the period leading up to a molt.

During this stage, the spider is preparing to shed its old exoskeleton and develop a larger one beneath it.

Depending on the spider's age and species, premolt can last anywhere from a few days to several weeks.

Common Signs of Premolt

Refusal of Food

One of the earliest signs.

A spider that normally eats enthusiastically may suddenly ignore prey.

This is often perfectly normal.

Increased Webbing

Many spiders begin reinforcing or expanding their silk hammock.

The hammock may become:

  • Thicker

  • Denser

  • More enclosed

This retreat will often serve as the molting chamber.

Reduced Activity

A spider preparing to molt usually becomes less active.

You may notice:

  • Less exploration

  • More time resting

  • Longer periods inside retreats

Extended Hiding

Many spiders remain hidden for days or even weeks before molting.

This behavior is particularly common in larger juveniles and subadults.

Darkened Appearance

Some spiders appear darker before molting.

This occurs because the new exoskeleton is developing beneath the old one.

What To Do During Premolt

Leave the Spider Alone

This is often the best course of action.

Continue providing:

✓ Proper ventilation

✓ Hydration opportunities

✓ Stable temperatures

Remove Uneaten Feeders

If prey is ignored:

  • Remove it

  • Do not repeatedly offer new prey

Persistent feeding attempts may create unnecessary stress.

Avoid Handling

Premolt spiders should not be handled.

Allow them to prepare undisturbed.

What Is Postmolt?

Postmolt

Postmolt is the recovery period immediately after a successful molt.

The spider has shed its old exoskeleton but has not yet fully hardened.

This is often the most physically vulnerable stage of the spider's life.

Common Signs of Postmolt

Fresh Appearance

Colors often appear:

  • Brighter

  • Cleaner

  • More vibrant

Many keepers immediately notice a dramatic difference.

Increased Size

The spider may appear noticeably larger than before.

Growth is often most obvious in the abdomen and legs.

Soft Exoskeleton

Although difficult to see, the new exoskeleton is still soft and delicate.

The spider requires time to harden.

Continued Retreat Use

Many spiders remain inside their hammock after molting.

This is completely normal.

They are recovering—not hiding.

Limited Activity

Movement often remains reduced for a short period.

The spider is allowing its new exoskeleton to strengthen.

What To Do During Postmolt

Be Patient

Even though the molt is finished, recovery is still underway.

Avoid unnecessary interaction.

Continue Hydration

Maintain hydration opportunities while ensuring good airflow.

Wait Before Feeding

Freshly molted spiders should not be fed immediately.

Wait until:

✓ Activity returns

✓ Fangs darken

✓ The spider leaves its retreat naturally

Only then should feeding resume.

Avoid Handling

The new exoskeleton remains vulnerable.

Give the spider time to fully recover.

Premolt vs Postmolt at a Glance

PremoltPostmoltPreparing to moltRecovering from moltOld exoskeleton still attachedNew exoskeleton exposedFood refusal commonFeeding should be delayedIncreased retreat constructionContinued retreat useReduced activityReduced activityMay appear darkerOften appears brighterGrowth not yet visibleGrowth becomes visibleDo not disturbDo not disturb

The Most Common Mistake

Many new keepers see their spider emerge larger and brighter and immediately want to:

  • Feed it

  • Handle it

  • Photograph it

  • Interact with it

Resist the temptation.

Just because the molt is complete does not mean recovery is complete.

The spider still needs time.

When Should Feeding Resume?

A good rule of thumb is:

Wait until the spider is actively moving around and the fangs have darkened.

Depending on the spider, this may take:

  • A few days

  • A week

  • Occasionally longer

Patience prevents many avoidable problems.

Why These Stages Matter

Most molting complications do not occur during the actual molt.

They often occur because a spider is disturbed during premolt or postmolt.

Understanding these stages allows you to provide:

✓ Proper hydration

✓ Reduced stress

✓ Better husbandry decisions

✓ A safer environment

The Tiny Coven Approach

At Tiny Coven Jumpers, we encourage keepers to think of molting as a process rather than a single event.

Premolt is preparation.

Postmolt is recovery.

Both stages are equally important.

And both require the same thing from us:

Patience.

A Keeper's Rule of Thumb

If your spider is hiding before a molt, let it prepare.

If your spider is hiding after a molt, let it recover.

In both cases, the best thing you can do is provide a safe environment and trust the process.

Growth takes time—even for spiders.