Tarantula molting is when a tarantula sheds its outer shell to grow. Most tarantulas will molt while lying on their backs (though some will molt on their sides). It can be quite alarming to find your tarantula lying in a seemingly unnatural position, but this is a normal process for tarantulas. If you find your tarantula lying on its back, do not touch it as it is extremely fragile at this time. Here's what to expect during tarantula molting and how to properly care for your pet during this time.

What is Tarantula Molting?

Tarantula molting is the process by which a tarantula sheds its exoskeleton so it can grow. Tarantulas, like other arthropods, have a hard outer covering called the exoskeleton that provides support and protection. As the tarantula grows, the exoskeleton becomes too restrictive, and molting is necessary to accommodate its increasing size.

Time: Molting usually takes anywhere from 15 minutes to a full day, so keep an eye on your tarantula but do not handle it. You should be able to verify molting by the evidence left behind in the form of the molt, which looks just like another spider.

Frequency: Young growing spiders will molt up to once a month while older spiders may only molt every year or two. Adult males will only molt one time after reaching maturity due to their shorter lifespans.

Signs of Tarantula Molting

There are several signs that a tarantula is about to molt, and some are more subtle than others. Note that some of these signs can occur for other reasons besides molting:

• Lying on Its Back: Many people think that if their tarantula is on its back, it means that it is trying to die. This is not the case, and it is quite rare that a tarantula would ever be found dead upside down. It is more likely to be found dead with its legs curled under it than to be found lying on its back.
• Decreased appetite: A tarantula getting ready for a molt will usually stop eating, sometimes for as long as a few weeks before a molt.
• Decreased activity: A tarantula getting ready to molt will often become very slow and sluggish.
• Bald spot: Tarantulas also sometimes develop a bald spot on their abdomen that grows increasingly darker as the molt draws near (a bald spot can also occur in New World tarantulas that have been kicking off their urticating hairs). After molting, the bald spot will be gone.
• Increased use of webbing: Tarantulas may make a mat out of silk for molting.
• Dull coloration

While it may look like your tarantula is in distress, molting is a natural process. Tarantula molting is not painful, but it does make them fragile and vulnerable to injury for a few days.

How to Care for a Molting Tarantula

If you notice the signs that a molt is impending, make sure the humidity in the tank is ideal and the temperatures are right for your specific kind of tarantula. A proper environment is important for a successful molt.

Make sure there is no uneaten prey in the tank, as even a cricket can seriously injure—or even kill—a molting tarantula. Do not feed a newly molted tarantula for at least a week to prevent new crickets from biting your tarantula before the exoskeleton has time to harden. The newly molted tarantula is so sensitive that even an innocuous little cricket can cause serious harm to them.

As the old exoskeleton is shed, the tarantula's body will be soft and extremely vulnerable. Though the actual molting usually takes a few hours, the tarantula's body will also be soft and vulnerable for several days before the new exoskeleton completely hardens. For this reason alone you should never handle a molting tarantula, or handle it right after it molts. You should also try not to startle or scare your tarantula during this time.

The molt they leave behind is harmless and can be left in the habitat. Some tarantulas will move the molt or even curl up in it, but these are normal behaviors. It may appear as if the tarantula is eating the molt if they use their fangs to handle it.