How Do I Know if My Tarantula Is in Premolt?

Don’t panic…learn to watch for the signs.

Fewer facets of tarantula keeping can cause more excitement and confusion for the novice keeper than premolt. This is the point where the tarantula usually stops eating for a bit and prepares its body for the stresses of molting its exoskeleton. As part of the joy of keeping tarantulas is experiencing their growth, an impending molt should be a joyous occasion.

However, as many newer keepers aren’t familiar with what premolt entails or looks like, it can also be a confusing situation that leads to worry and stress. Couple this with the fact that premolt periods can drag on for weeks, and you have the makings of a concerned keeper.

Part of the issue is because we have all grown up keeping pets that need to be fed daily in order to stay healthy. So, when our beloved little spider suddenly stops eating for several weeks, years of experience preys on our nerves and the worrying begins. Should I try feeding again? Does she need more water? Is the enclosure too large? Is she sick? Should I dig her out of her den? These are the questions that dog the novice keeper as he watches his pet, waiting for some sign that everything is totally normal.

I went through it myself the first time my little L. parahybana sling suddenly closed off the entrance to its den and buried itself for over a month. I worried that the poor little guy was trapped by a cave-in or had died. Luckily, I chose to leave him alone instead of trying to dig him out, as when he finally reappeared it was with a new exoskeleton and an extra 1/4″ of length.  Since then, I’ve learned to observe and recognize the signs of premolt.

Are you thinking that your specimen might be in premolt? Here are some telltale signs to look for…

1. The tarantula stops eating

This is probably the most obvious and common sign. You’ve been feeding your specimen regularly for several weeks, and suddenly it stops eating. Most species will stop feeding during their premolt period (although there are exceptions) as they prepare their bodies for the arduous process.

That is not to say that a tarantula might not stop feeding for other reasons. The G. rosea is known to fast for long periods of time, even when not in premolt. A stressed tarantula may also refuse food. Therefore, consider some of the other signs as well.

2. The tarantula has a fat, shiny abdomen

Most tarantulas ready for premolt will sport nice, plump abdomens up to 1.5 times the size of their carapace (or even larger for an over-stuffed specimen). If your tarantula has a nice, bulbous booty, and she has stopped eating, chances are she’s in premolt. As the flesh around the area stretches, the abdomen may also appear to be shiny.

The shininess is often more evident in slings than their older, much hairier counterparts. My little G. pulchripes, G. rosea, and L. parahybana slings all get “shiny hineys” whenever they are entering premolt. My P. cancerides slings and juveniles look like little grapes ready to pop when they are in premolt.

A female LP in premolt. Notice the shiny abdomen. This is particularly noticeable as she has kicked all the hair off. Also, the abdomen is very dark.

A female LP in premolt. Notice the shiny abdomen. This is particularly noticeable as she has kicked all the hair off. Also, the abdomen is very dark.

3.The tarantula’s abdomen and overall color darkens.

As the new exoskeleton forms under the old one, the spider will often darken up a bit. This is particularly evident on the abdomen where new hairs can be seen through the stretched skin here. Many of my slings will have a dark spot on their abdomens when in premolt, and it will continue to grow the closer they get to the actual molt. For species that do a lot of hair kicking and therefore have a bald spot, this darkening is especially evident.

G. rosea sling in premolt. Notice the large, shiny, and dark abdomen.

G. rosea sling in premolt. Notice the large, shiny, and dark abdomen.

My L. itabunae in premolt. Notice the shiny abdomen and the dark patch forming .

My L. itabunae in premolt. Notice the shiny abdomen and the dark patch forming .

4. The tarantula becomes slower and more lethargic.

Not all of the indicators are physical; an observant keeper should notice some behavioral changes as well. Besides not eating, most of my tarantulas that are in premolt become less active and often more secretive. Keep an eye on your tarantula, and along with the physical signs listed above, look for a change in behavior. Some of my most hyper species become noticeably sluggish when they are in premolt. For example, my GBBs tend to be fast little buggers who are constantly moving around their enclosures. However, when in premolt, they often become much more sedentary, sitting in one spot and often tucking themselves away behind their cork bark. Speaking of secretive…

5. The tarantula has buried itself in its den.

I frequent the Arachnoboards forum, and there is usually at least a post a week by a concerned keeper who wants to know if his/her buried T is okay. Heck, this is the situation that caused me alarm when my LP buried itself during a molt. Many tarantulas will retreat to their burrows and close of the entrances when entering a premolt period. My LP slings, M. balfouri juveniles, and G. pulchripes slings all bury themselves before a molt. Some things to consider if your T buries itself due to premolt.

They are not in danger.

They will not suffocate.

They have not been buried alive.

They do not need to be rescued.

The tarantula is just looking for some privacy and security during this vulnerable period. The tarantula will reopen its den once is has molted and hardened up. DO NOT freak out and try to dig the poor creature out; you only run the risk of distressing the animal and possibly interrupting its molt.

6. The tarantula has constructed a hammock-like web “mat” in its enclosure.

This web is referred to as a “molt mat”, and it is where the tarantula will flip over on its back when it molts. You may catch your premolt T laying layer after layer of web in a small area, and some of the new world species will actually kick hairs on the web as a form of protection. If you see this behavior, it means that your tarantula is about to molt very soon, usually within a day. For arboreal species, they will sometime build elevated “hammocks” off the ground for their molt mats or seal themselves in their funnel webs. This behavior serves the same purpose.

My female LP during a recent molt. Notice the molt mat on the left hand side of the photo.

My female LP during a recent molt. Notice the molt mat on the left hand side of the photo.

One more thing to remember for those who have not witnessed a tarantula molt…


That’s right, this is normal behavior; this is the position they get in to molt.

DO NOT touch a spider in this position.

DO NOT flip over a spider in this position.

DO NOT throw away, flush, or bury a spider in this position.

DO NOT blow on it.

DO NOT spray it with water.

DO leave it alone and let it complete the exhausting task of molting in peace. Molting is a natural occurrence for a tarantula, but it is also a period where they are quite vulnerable. Any fiddling with the animal could prove deadly to the T.

Hopefully, the photos and explanations above will help other keepers recognize and enjoy their tarantulas’ premolt without worry. Keep in mind, there is no set time for how long a tarantula can be in premolt. For slings, it can take anywhere from couple weeks to a month. Adult species can often spend several months in premolt. My 3.5″ B. smithi stopped eating and secluded herself for two months before finally molting. Conversely, my 3.5″ L. parahybana female molted two weeks after her last meal. Don’t panic if your animal takes a while; it’s a very natural process, and it will molt when it is ready.

And, for anyone curious as to what a tarantula molt looks like, please check out the following video.


204 thoughts on “How Do I Know if My Tarantula Is in Premolt?

  1. So I just got my husband a rose and we have only had it for one day. The day we got it it was staying on the the side of the 5gallon tank we have. Then later in the day it just sat in a corner. Some signs of premolt are there. It hasn’t eaten. It does look as though abdomin is going bald and plump. On the second day less then 24hrs it was a little active. But now still less then 48 hrs of owning it it just sits motionless on the side half on glass half on bedding. No burrows, no webs. Nothing is this normal at all? And it’s right side up not upside down. Age? Sex? No ideas. Sorry


    • Hi, Jana!

      Do you know how large she is? Do you, perchance, have a photo of her?

      Is the substrate dry or wet?

      What you’ve basically described is pretty typical rose hair behavior. I’ve had mine for 20 years, and she moves maybe once a week. They are a VERY sedentary species, which has earned them the nickname of “pet rock”.

      It can take any spider a few days to a few weeks to settle in, so she might move around a bit more once she has settled. She will most likely not burrow, and they throw down very little web.

      This is a species that’s known to fast, so it’s possible that she’s just not in an eating mood at the moment. As long as her abdomen is plump and she has a bowl of water, she’ll be fine.

      Here is a husbandry article I did on rose hair care, if you’re interested and haven’t seen it already.

      Hope that helps!


  2. This page was such a relief to me! But that’s only for one of my slings. Now I have one that molted just yesterday but it still has a black spot on its abdomen. Do you why that is?


    • Hi, Johnny!

      What type of sling is it? I’m guessing that you might be seeing a “mirror patch”, or a group of urticating hairs on the abdomen that reflect light differently.

      Can you send me a photo?




  3. Hi guys,

    Please help! I have my first T (Mexican red knee) can never spell the correct term.
    Anyway I have had her for about 3 months now. I feed her twice a week (one large roach) anything more was dying.
    Tonight doing my routine clean( just picking out any leftover food, and anything that didn’t look to clean) she was off her log so I decided to move it, I found 3 dead uneaten roaches and a sneaky one alive in hiding. So given this it seems she hasn’t ate in likely two weeks.
    I have found since I got her she has always seemed quite lazy and only takes food that is practically handed to her.
    Is this normal? Or should she be able to find any food? Her enclosure is about 3 times her length so not to large. She’s about 1 and a half, and hasn’t molted since I got her.
    Is this pre molt behaviour? I haven’t noticed a large difference with her abdomen.
    How long refusing food for a pre Molt?
    Any advice would be greatly appreciated!
    Can’t find an option to post a picture on here?

    Liked by 1 person

    • Hello! You say she is about 1 1/2, so I’m assuming that she’s still a sling or juvenile? What size is she?

      Two weeks is not a long time for a tarantula not to eat. I have some that will go six months or more without taking a meal. They can go very long periods of time without eating and still be healthy. I definitely wouldn’t worry yet. 🙂

      If she’s in premolt, the length of time she takes to molt will differ depending how large she is.

      If you want to email me a photo, send it to .

      Hope that helps!



  4. Striped Knee Tarantula
    -What should I do if the time has come to clean the tank and she is still in its molting or pre molting stage?

    -Besides the legs curling under a tarantula, are there any other signs of a tarantula being dead?

    -Once she has built her mat, should that be a sign to lighten up on feeding or just stop feeding until her molting is completely over?

    I know I shouldn’t worry, but she has been pre molting for 2 months soon to begin 3, and she still hasn’t lost any hair giving her a shiny abdomen.

    Liked by 1 person

    • Hi, Cade!

      – Is there mold, mites, or something else that might cause the T immediate harm? If not, I’d definitely wait. Are you just spot-cleaning boluses?
      – Leg curling under and the abdomen becoming deflated are the most common signs.
      – It depends…some tarantulas will build a feeding mat, which they used to detect approaching prey. This is NOT a sign of premolt. If she is laying down a molting mat, then you definitely want to keep prey out of there; it means a molt is coming VERY soon.

      My striped knee (I’m assuming it’s an A. geniculata) goes quite a long time in pre molt with no issues. How large is your T?


  5. Hello i just bought my first tarantula so happy a mexican red knee tarantula (might be a fireleg ill give you a picture) and she/he is not moving much and her color is dull can u tell me if she is pre molting? id be happy to send u some pictures any help is greatly appreciated as i am new to this hobby

    Liked by 1 person

  6. Thanks for all the info. Ive noticed my T acting very sluggish and not eating like normal so i started worrying. All the premolt signs you mentioned my T is showing. My mind is at ease. I thank you.


  7. Hey, Tom. I have a huge concern for my tarantula. I believe it’s a female. She is a B. smithi and is 2.25 inches long. I don’t know if she is in fact in premolt or not. She has not eaten for over a month now. I sprinkle one corner of her enclosure where her water bowl is located once a week. She doesn’t react to the crickets and dubia roaches I’ve offered her. Even when the insects were touching her legs, she would stay still. I’ve tried using a grass leaf right outside her burrow to bait her to come out, but almost all the time she would stay still or go deeper in her burrow. It’s hard to determine if her abdomen is changing color for I am a beginner and she is my first T. I have eco earth as my substrate (rehydrated the brick). It’s to note that she has been moving a lot. It is also winter where I am, and the temperature in my house flictuates 68-78 degrees.

    She has molted once back in July. She retreated to her burrow and blocked off the entrance. I was concerned, but I soon found out that she molted after I poked a hole at her entrance. Can I send you pictures of her for your thoughts and suggestions?

    Liked by 1 person

  8. Hey, I just bought a mexican red knee tarantula earlier this week and it hasn’t eaten ever since, I know it has been only 4 days but im still a bit worried. He/she is about 2 inches (1 one year old) but when I took her out of the box I noticed it just had molted so it would be unlikely that it will molt again… I did notice some darker spots on its abdomen. It doesn’t move a lot and as I told you before disn’t eat either. Is it premolding or just getting used to his new home?
    Also, whats the best temperature for a smithi? Some say even 60 degrees is enough for it but others suggest it should be atleast 68…
    Also about the spraying of water does it really haveto be done every day? Isn’t it gonna be fine with just a bowl of water?
    Thxfor responding!


    • Hello, Thomas!

      Congrats on your red knee! They are a great species!

      If it is about 2″, your spider is probably closer to two or three…these grow VERY slowly. The dark spot you’re seeing might be the urticating hair patch. Is it on the top of the abdomen?

      If it was just rehoused, it can take a few weeks for it to settle in. They often won’t take food until they become accustomed to their new surroundings. Also, if it just molted, it might not be ready to eat yet. I would give it some time. They can go months without eating with no issues.

      These guys can definitely do well in the 60s, but lower temps can make them go off feed for a bit. Lower temps won’t harm it; you’ll just get a slower growth rate.

      I wouldn’t spray it at all. At that size, a water dish should be plenty. If it’s really dry in your house due to the heat running, you can moisten just a corner of the substrate.

      I hope that helps!



      • Ok thanks for answering me so fast! The spots are indeed on top if its abdomen but it still has all his hairs so I think it won’t be molting soon. The temperature is always around 68 so that’s ok too. I was just a bit confused to see a big spider being scared or not wanting to eat a small cricket. I hope he will eat soon.


      • No problem! It’s probably not that it’s scared but just not hungry or ready to eat yet. I know it can be stressful to get a new pet an not have it eat for a bit, but these animals can go a very long time without food. I have one T at the moment that hasn’t eaten in six months. It’s totally fine. 🙂


  9. Hi! I got a guyana pink toe on tuesday, my first spider, and so far she hardly moves unless provoked by me via a very soft unused makeup brush so as not to hurt her. I’ve watched a lot of videos on youtube about these spiders and I thought this species would be an active one. I’ve given her two crickets in the past two days because her abdomen looks pretty small and she’s eaten both of them. I try to keep her enclosure moist because I know she’ll need higher humidity and heat. It concerns me that she doesn’t really move around a lot and sits at the bottom of her enclosure, because I know she’s an arboreal species. Does she just need more time to adjust? I think she’s pretty young, less than a year based on her size. I think she’s maybe 1.5″, but she has some pretty vibrant colors. Let me know what you think I should do to ensure she’s not distressed or sick!

    Liked by 1 person

    • Hello, Jennifer! Congrats on your first tarantula. 🙂 Be careful: this hobby is ridiculously addictive!

      Could you possibly send me a photo with your setup ( She may just need more adjusting time. Does she have a hide and fake foliage?

      Also, be careful with humidity with the Avicularia species. There are a lot of care sheets out there that say they need moist conditions, and that can actually kill them. I keep mine with a water dish and spray their webs twice a month or so to give them a chance to drink off of them.



  10. Hi, My son has 2 T’s he got for his christmas – a white knee and a GBB – both were ferocious eaters to begin with and now the GBB is not eating anything, we have to remove the crickets the next morning every time we put them in, how long doe they usually go in pre-moult?

    The white knee I am not sure if its in pre-molt, its blocked the entrance to its hide – the front fully and left a little bit at the back – I am not sure if I should keep trying to feed it or just leave until it molts?

    Both are juveniles

    We had a pink toe die this year, it wouldn’t eat anything and then started to shrivel up


    Liked by 1 person

    • Hi, Milo.

      Pink toes can be a bit more “fragile” than other species, so that doesn’t surprise me.

      I’ve raised two GBBs from slings, and generally the only time they don’t eat is when they are in premolt. As slings, mine would fast for a 2-3 week or so before molting. As adults, it can be closer to a couple months. I would stop offering food for a bit. I’m assuming its abdomen is plump?

      As for the white knee, when they block of the entrance, it’s usually a good indication that they are in premolt. When it opens back up, expect a bigger and hungrier spider.

      I hope that helps!



  11. Thanks, yes big help, knowing how long to moult and how long before we should worry about it being something else is the unknown for beginners – the white knee is very big so think this could be ready to moult – will wait another week and see how it is

    The GBB is still moving around but not showing any interest in food, the crickets pass under it and it just stays in position, the abdomen is not massively plump – i could send a photo if that would help?


    • I’m so sorry for the delay…I just saw this! Please, feel free to email me a photo.

      Generally if they bury themselves, they know what they’re doing. Eventually, it’ll open its den back up, drop the molt outside, and be ready to eat again. 🙂


  12. Hi, i got a G. Pulchipres as my first Tarantula last week. She is about 5cm (the size of a small water botle cap) in legspan and she doesnt react to roaches even if they touch her… I feel like she might me in premolt but she doesnt have a grape like abdomen but has a darker area with a little shinny place on top of abdomen.. How often does a G. Pulchipres molt in that size? 3-4 months? And how long can a sling go without eating? i may send a photo if needed..

    I hope someone can help, and thanks for your time 🙂

    Greetings from Portugal.

    Liked by 1 person

    • Hello, Rodrigo!

      Congratulations on your first tarantula. Be careful…this hobby is VERY addictive. 🙂

      She could very well be in premolt. The dark spot you’re seeing is a “mirror patch”, or a patch of urticating (irritating) hairs a tarantula can kick for defense. When it’s in premolt, the abdomen will usually look stretched and shiny all over.

      I have two G. pulchripes that I got a less than one cm slings. They would both go all winter, five months total, without eating. They seemed to sense when it was colder out, and would fast. Once spring hit, they would pop out again, hungry and ready to eat. They can go long stretches without eating, so I wouldn’t worry there. This is also a slow growing species, so it can be several months between molts.

      You can certainly send me a photo. 🙂

      Hope that helps!



      • Thanks for the fast reply! I just sent you the photo by my gmail reply, maybe its not the best way tell me if you received the photo and if not, how can i send the photo? 🙂


  13. Thanks for this. It was helpful. I just bought a tarantula last week. It’s a spiderling. I did a lot of reading up on raising them but wasn’t prepared for what just happened. I went out with my son before, and the tarantula was fine when we left. When I returned two hours later, she looked dead, all crumbled up. In a panic, I shook the little container that she is in to see if she moved. She didn’t. I thought she was dead. But moments later, her little legs slightly moved, and within a matter of minutes, I realized she was probably molting. Thank God I didn’t kill her in my panic of shaking her. This is nerve wrecking! It’s like having another baby in the house😁

    Liked by 1 person

    • Hi, Thomas!

      You’re most welcome! I’m glad that this helps folks, as I went through the stress of trying to recognize premolt when I first got into the hobby. And I hear you about thinking she was dead. I almost buried my rosie the first time she molted for me because I thought she had died. That would have been terrible (especially as I still have her 21 years later! ). I know exactly what you’re feeling, bud! I’m so glad to hear that it ended well. 🙂

      All the best!



  14. So I got my very first tarantula a little over a year ago, and I got it as a baby (it was only about a month old when I got it). Also I’m just going to use She since I havent been able to figure iut the sex of it. I have a few questions. She’s a curly hair, and she hasn’t burrowed since moved her from the little container she was in when I bought her, is that a problem? It’s been over a year. Also, I just added some water to her dirt and I checked it and her entire tank looks fuzzy ontop now, could it be mold and should I be concerned? My last question is about molting, she looks like she’s getting close to molting but she hasn’t eaten in somewhere around 3 or 4 months, and she hasn’t started molting. Should I just have more patience with her? Also if anyone has any tips on keeping a curly hair, the advice is much appreciated. Thank you.

    Liked by 1 person

    • Hi, Shay!

      I use the pronoun “she” for all of my unsexed ones, so I totally get it. 🙂

      For curly hairs, you really don’t need too keep them too moist, I only dampen a corner of the substrate for mine. If you’re getting fuzzy white mold in the enclosure, it’s definitely too wet. I would rehouse her into something with dry substrate, then just moisten a corner or pour some water down the edge and let it dampen just the bottom layers. This might also encourage her to burrow.

      Could you send me photos of her and her setup? (

      Is her abdomen nice and plump? If so, she’s probably in premolt. How large is she now?

      Here’s my video guide on this species:

      Hope this helps!



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