What is Molting in Hermit Crabs and Why You Need to Know!
Molting in hermit crabs is a natural process that all hermit crabs go through as they grow and develop. It involves shedding their old exoskeleton and replacing it with a new one.
This process is essential for the health and growth of hermit crabs, but it can also be stressful and potentially dangerous if not properly managed by their caregivers.
During the molting process, hermit crabs will retreat to a hidden and secure location, typically underground.
They will then shed their old exoskeleton and remain in a state of vulnerability for a period of time while their new exoskeleton hardens and becomes functional.
How Often Do Hermit Crabs Molt?
The frequency of molting in hermit crabs isn’t predictable as it depends on their age, health of their habitat, their diet and more. Molting tends to be more frequent in younger hermit crabs, as they grow and develop faster.
How Long Do Hermit Crabs Molt?
The time it takes a hermit crab to do a full, successful molt depends on age. The older the hermit crab, the longer a full molt can take.
Fred, below, is approximately 15 years old. He began digging October 13th, and re-emerged on December 1st, for an approximate 6 week molt period. However, the timing does vary and it’s definitely not predictable!
It’s important for new hermit crab pet parents to know that there is NOTHING to worry about if your hermit crab goes missing for a couple of weeks. And the older they get, the longer they will remain buried.
Side note: IF a hermit crab never re-emerges… you do NOT need to dig them up. The circle of life happens brilliantly, and you’ll be protecting the habitat far more by NOT digging into the substrate.
Some hermit crab owners want to dig up dead hermit crabs. NO NEED, and it can issues and stress. Other hermit crabs will eventually find the hermit crab’s exoskeleton and eat it for extra calcium.
Eventually when you go to replace the substrate (recommended to change substrate once a year for most habitats) you’ll simply find an empty shell deep down, no sign of a dead hermit crab at all.
What Happens During the Molting Process?
The molting process happens completely underground, so there is some mystery surrounding the process! You’ll never see it happening, so here are the main things that happen:
1. Hermit crab eats and drinks a lot more in the days just before they are planning to molt (you may or may not even be aware this is happening)
2. Hermit crab digs into the substrate, burying down a few inches from the surface or as far down as he feels comfortable (they don’t want to be close to the surface because molting gives off a special smell that attracts other hermit crabs, who may want to eat their exoskeleton for the calcium… but the MOLTING hermie needs to eat it or he’ll die). This is a big reason why hermit crab habitats NEED plenty of substrate!
3. Hermit crab will remain buried for potentially weeks and even a couple of months, depending on size/age as they shed their exoskeleton, grow their new one, and eat the old for calcium/strength. Note: the molting process is NOT easy for hermit crabs, though it’s crucial to their life cycle. It’s stressful for them, so make sure to keep the habitat within the same paramenters (humidity, temperature) as they are normally used to, keep the water clean, keep feeding them (even if you only have ONE hermit crab because you never know when he’s going to re-emerge!).
4. Once their new exoskeleton is solid and strong enough, they’ll make their way back up to the surface. They’ll be thirsty and hungry. The hermie will have more energy, seem happier, and will probably be brighter and prettier than before! Whether or not you can tell, he’s a little bigger now so make sure you have plenty of extra empty shells for him to choose from! He will most likely change shells a few times over a couple of days while choosing his favorite!
What can you do to help your hermies during this stressful molting time?
- Always have plenty of substrate… the bigger and older your hermit crabs are, the deeper your substrate should be inside their habitat
- Continue to spritz the habitat with de-chlorinated water to add moisture and humidity to the air (I also spray a little extra 2-3 times per week on the surface of the substrate, like a quick South Florida rain shower), this helps keep them hydrated
- Do NOT dig into the substrate! Never handle hermit crabs during the molting process
- Keep feeding and adding clean water daily, even if you only have one molting hermie!
- Watch for any bullying behavior with other hermit crabs in the habitat… take action IF you have a hermit crab that looks like they are molting on the surface (not good). Hermit crabs need to molt alone, away from other hermies… so if they are doing a surface molt (indication something is wrong), try to protect them by placing something over them to protect their space (but they have to be able to breathe).
In conclusion, molting is a natural and CRUCIAL process each hermit crab goes through many times throughout their life. Molting is a necessity in order to grow. Watch the behaviors of your hermit crab pets paying close attention to when they dig below the surface and bury themselves, so you can help ensure a smooth and successful molting process.
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Substrate in this Ikea Milsbo Hermit Crab Habitat Hack is approximately 8″ deep. We use a mix of natural sand and coco-fiber (about 3/4 to 1/4).
Extra Shells
At some point, your hermit crabs will eat a little more, sit in their water bowl a little longer, and disappear into the substrate. They’ll dig down and hide away from your other hermit crabs, disappearing for days or weeks. They will be molting, and it’s a normal and an essential part of their life cycle so don’t worry!
Here’s more information on types of shells.
During molting, they shed their exoskeleton. When they emerge again, they will be a little bigger and happier. And they’ll be looking for a new home. It’s essential to provide extra shells in the habitat, of the same size and slightly larger. Hermit crabs LOVE trying on new shells.
If you have Purple Pinchers, the bigger and older they get, the more they seem to prefer Turbo Shells of any other type. Most likely it is because turbo shells are a medium weight, which gives them security in protecting their most vulnerable abdomens plus they have a circular opening. The also have a compacted curve which makes climbing and maneuvering in tight spaces much easier than an elongated shell like a whelk.
Temperature and Humidity Gauge
Essential hermit crab supplies should always include a thermometer/hygrometer. Why? Depending on where you live (climate), where you keep your hermit crab habitat (indoors, covered patio) and what type of hermit crabs you have… your parameters could be very different than what your pets need to remain healthy. Monitor the habitat’s parameters: healthy temperature and humidity are important to the health of hermit crabs. The temperature should be in line with the climate of Key Largo or a Caribbean Island IF you have Purple Pincher hermit crabs (the most common type of hermit crab found in the U.S. pet industry).
Temperature in this part is most often in the 70’s to low-90’s throughout the year. In winter, temps can dip for a day or two to the 30’s.
At night with an ocean breeze temps are often in the 70’s. In high summer, temps during the afternoon can reach low to mid-90’s.
If you don’t live in South Florida, the Florida Keys or a Caribbean Island, or you do and run your AC on very cold… you’ll need to watch your parameters. Does your hermit crab habitat need heat?
Purple Pinchers are the most resilient type of hermit crabs. Other types need higher heat and humidity to survive. Here’s more on types of hermit crabs here.
Last update on 2024-05-08 / Affiliate links / Images from Amazon Product Advertising API