Why Is My Jumping Spider Hiding in Its Hammock? (Read Before Opening!)

You’ve had your jumping spider for a few weeks, and they’ve been active, exploring, and hunting. But suddenly, they built a remarkably thick, opaque silk tent (called a hammock) at the top of their enclosure, and they haven’t come out for days.

New keepers are often seconds away from poking the hammock open at this point — a reaction that experienced keepers warn against in the strongest terms. “Don’t touch it. That’s a molt.” Those five words have saved more spider lives than any piece of equipment.

If your jumping spider has sealed itself inside a thick hammock, they’re preparing to molt (shed their exoskeleton). Opening the web right now could literally kill them. If you’re new to these spiders, the complete beginner’s guide is a good place to start.

The Molting Process Explained

Because a jumping spider has a hard outer shell (exoskeleton), they must periodically shed and replace it. To grow larger, they build a safe room, shed their old skin, and wait for their new, larger skin to harden.

This process takes time. During pre-molt (days 1-7), they build a hammock so thick you can barely see inside and will refuse food. The actual molt (several hours to a day) is when they push out of their old skin - during this time, their new body is as soft as jelly. Post-molt (days 1-4) is when they stay in the hammock while their new fangs (chelicerae) and exoskeleton harden.

What Happens Inside the Hammock?

During pre-molt, the spider’s body secretes a hormonal fluid that separates the old exoskeleton from the new one growing beneath it. The spider then lies on its back or side inside the hammock and slowly works its way out of the old skin, beginning with the carapace (head). The legs and pedipalps are pulled free last. This is the most delicate stage. Any disturbance or vibration during molting can cause a leg to get stuck, resulting in a deformed molt that the spider may not survive.

How Often Do They Molt?

Young jumping spiders (slings) molt frequently, every 2-4 weeks, because they’re growing rapidly. Adults molt less often, typically only 1-2 times per year. A mature adult female may continue molting periodically, while mature males often stop molting entirely and spend their remaining energy on mating.

Why You Should Never Disturb the Hammock

If you rip open the hammock while the spider is soft, the sudden stress can cause a “mis-molt” (getting stuck in their old skin), or a short fall could rupture their soft abdomen, which is 100% fatal.

Even lifting the enclosure gently can sometimes be enough to startle a molting spider. Place the enclosure in a quiet, low-traffic area during the molting period and resist the urge to check on them.

What You Should Do Instead

While you can’t feed them or play with them during a molt, you have one job: maintain the humidity.

Molting requires moisture to help the old skin slide off. Lightly mist the side of the enclosure (NOT directly on the hammock) once a day. Keep offering water droplets on the acrylic walls so they can drink if they briefly poke their head out. Remove any live crickets or mealworms from the tank immediately. A live cricket will eat a molting spider.

How to Tell When Molt Is Complete

Once the spider emerges from the hammock, their colors will look vibrant and their movements will be sharp and deliberate. You may find the old exoskeleton (the molt) crumpled up in the hammock or on the enclosure floor. This is a good sign that everything went smoothly.

First Feeding After Molt

After molting, wait at least 3-5 days before offering food. The spider’s fangs need time to fully harden: attempting to bite prey too soon can bend or damage them. Start with a small, easy prey item like a fruit fly rather than a large cricket. Watch carefully to confirm the spider is able to catch and subdue the prey. If they ignore it, remove the prey and wait another 2 days.

When to Worry

Most molts go smoothly, but sometimes things go wrong. Signs of a problematic molt include:

• The spider remains in the hammock for over 2 weeks without emerging
• You can see the spider is visibly deformed (curled legs, bent fangs)
• The spider has partially emerged but is stuck in the old skin
• The spider has left the hammock but is walking oddly or dragging legs

If you notice any of these signs, consult a knowledgeable jumping spider keeper or exotic vet. Don’t attempt to “help” the spider out of its old skin. Intervention by inexperienced keepers almost always makes the situation worse. The Bugnook’s jumping spider molting guide is an excellent resource for understanding what to expect during molting.

In a week or two, your spider will emerge looking brighter, fluffier, and hungrier than ever. Watching a regal jumping spider crawl out of its old exoskeleton is a small spectacle — and the way it stretches each leg one by one afterward is oddly endearing.