Crabs always Underground?

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Topic author
Graz73
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Joined: Wed Aug 14, 2019 8:26 am
Location: OH

Crabs always Underground?

Post by Graz73 » Wed Aug 14, 2019 9:08 am

Hi I'm new to hermit crabs. I've learned a lot on the internet about their care, but came here for more specific advice:

My concern:
My 2 medium and one small crabs spend ALL of their time underground in sand burrows. We even smoothed out the surface sand so we could see their footprints, if they came to the surface when we were not looking. They rarely leave their burrows at all even for food or water. But, if I listen closely, I can sometimes hear scraping inside the tank coming from under the sand. So at least one of them is still alive, and there is no "fishy" smell.
The main reason I'm writing all of this: It seems like it has been too long for molting! Under the sand since mid-june for one of them. Under the sand roughly a month for the other two. I'd like to clean out the crabitat, and reorganize it, but also don't want to disturb them if they are really molting.

Here is some more background info so you'll know more details:

• My son bought 2 medium crabs and one large crab in early June at the beach.

• Back in Ohio, we set up a better habitat:
- 10 gal tank
- non-Chlorinated fresh and salt water bowls with sponges in them which we change about weekly
- We mist the inside of the habitat daily
- an area with coconut based substrate for them to dig in (which they rarely ever use)
- a large "hill" of shell-based sand for them to dig tunnels in.
- Under the sand I've got a plastic aquarium tray with holes in it to help w ventilation so air and maybe water can get under the sand.
- a rock-feature for them to hide in and climb on.
- lots of extra shells for them to swap between.
- tank temp between 78-85 degrees
- various foods: hermit crab pellets, rice, fruits, vegetables, and occasional bits of meat
- we remove poop or any food that goes bad as needed

• Zeus: Our large crab was missing one back leg when we bought him. After just a few weeks, as we were getting this new habitat fixed up, limbs started falling off and he died. (Possibly from stress?)
• The other 2 medium crabs seem to do ok:
- Artemis: - Changed to a bigger shell.
- Climbed around on the rock feature a lot and was sort of playful
- Eventually after a month of "normal" behavior dug into the sand and has not been seen in weeks.
- Apollo: - Changed to a bigger shell.
- Mostly liked to dig tunnels and stay underground
- Only seen active once in the last 6 weeks. (Pulling a piece of chicken underground!)
• We later bought a 3rd smaller crab from the pet store:
- Leo
- Seemed to get along OK w the existing crabs, sometimes hanging out near "Artemis"
- Eventually tunneled underground and has not been seen in a month.

Is there anything I should do about this?
Any advice or questions are much appreciated!! Thanks!

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Hermiesguardian
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Re: Crabs always Underground?

Post by Hermiesguardian » Wed Aug 14, 2019 10:05 am

Welcome! Molting can take up to several months. I've heard when it reaches 8 months you can get concerned and maybe dig for them. Here are a few tips to make your conditions as best as possible for them to be happy and healthy. A 10 gal tank is ok with 2 small crabs. If yours are true mediums then try and find a larger tank. You can find good deals on craigslist or the apps offerup and letgo. Bigger is always better.
Your substrate needs to be a minimum of 6 inches across. Or 3 times the height of your largest crab. Whichever is deeper. It needs to be mixed with dechlorinated fresh or salt water to sandcastle consistancy. Prime is the most recommended dechlorinator and add Instant Ocean for the salt. Pools need to be deep enough for them to fully submerge with a safe way in and out. Some use all eco earth for substrate or all playsand. Most use a mix because it holds moisture and shape the best. I don't know what you mean by shell based sand. If it's calcium sand that's bad for them. It can harden when wet. Too much misting can lead to flooding. Do you have a thermometer/hygrometer? It's very important to know the actual temp and humidity. Humidity has to be a minimum of 80% so they can breathe. They have modified lungs. Ditch the sponges. They hold bacteria. What kind of lid does the tank have? It should be completely sealed to hold in humidity. Lots of things marketed for hermit crabs aren't good for them. Such as the pellets. Check out the safe/unsafe food list and food pyramid. They need protein and calcium daily. I know it may seem overwhelming but once it's set up properly the rest is pretty easy. Many of us have night vision cameras set up in the tanks to watch their nighttime antics.
raising son's dog, Dante. Husky/hound.
Raising daughter's hermit crabs, Shelder, Paras and Derek. Added 2 more of my own (of course) Pete and Stryper. Former mommy to 2 guinea pigs and beloved cat, Nissi


Topic author
Graz73
Posts: 5
Joined: Wed Aug 14, 2019 8:26 am
Location: OH

Re: Crabs always Underground?

Post by Graz73 » Wed Aug 14, 2019 10:24 am

Thanks for all the tips. I'm sure they'll help at least a little!

What is defined as "Medium"? I'd guess these guys are roughly 2 inches square. Is that "small"? The other one we got from a pet store is a lot smaller. Maybe 1 inch.

Should I spray some dechlorinated saltwater or freshwater into the existing sand? (It is a pretty big mound, bigger than you described) I don't want to flood the crabs tunnels, but if the extra water is good for them, that might be an easy thing do do to help them.

The sand was previously "sandcastle" consistency but I'm sure it has dried out some since they've been buried in there.

I've got a thermometer. I can get a hygrometer, but don't have one. Any suggestions?
Also, how do I keep it humid enough in there? Just keep the lid sealed better? We've got a pretty good lid w few gaps.

easiest source of calcium?


Thanks again!

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curlysister
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Re: Crabs always Underground?

Post by curlysister » Wed Aug 14, 2019 10:31 am

The soft guideline is four months - anything less than that is totally normal and no need to worry, if all your tank conditions are good.

• Back in Ohio, we set up a better habitat:
- 10 gal tank
Curly - A 10 gallon will become too small eventually, and you will need to upgrade to a bigger tank - see the care sheet about tank sizes and crab sizes.

- non-Chlorinated fresh and salt water bowls with sponges in them which we change about weekly
Curly - Sponges are not needed, and only harbor bacteria, you can get rid of them. What brand of dechlorinator and what brand of salt are you using?

- We mist the inside of the habitat daily
Curly - Do you have a hygrometer? What is the humidity

- an area with coconut based substrate for them to dig in (which they rarely ever use)
- a large "hill" of shell-based sand for them to dig tunnels in.
Curly - substrate should be at least 6 inches deep, or three times as deep as your largest crab, whichever is deeper. I am not sure what 'shell-based sand' is. What is the brand? Many of us use a mixture of play sand (cheap in 50 pound bags at a hardware store), mixed with EE (coconout fiber). 5 parts play sand to 1 part EE is the most common mix, but some use different ratios. You don't ever need to clean out the entire tank once you have proper substrate, just spot clean, unless there is an emergency like a flood or bacterial bloom.

- Under the sand I've got a plastic aquarium tray with holes in it to help w ventilation so air and maybe water can get under the sand.
Curly - I'm not sure about this - hopefully someone with more tank building experience can chime in.

- a rock-feature for them to hide in and climb on.
- lots of extra shells for them to swap between.
- tank temp between 78-85 degrees
- various foods: hermit crab pellets, rice, fruits, vegetables, and occasional bits of meat
Curly - Commercial food like pellets is not safe for crabs. They need a varied diet, including protein and calcium daily. See the 'food' care sheets for the food pyramid, and the safe/ unsafe food lists.

- we remove poop or any food that goes bad as needed
"If there are no dogs in Heaven, then when I die I want to go where they went." -Will Rogers

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curlysister
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Re: Crabs always Underground?

Post by curlysister » Wed Aug 14, 2019 10:32 am

Oops...sorry HG, I was typing my reply at the same time you were replying!
"If there are no dogs in Heaven, then when I die I want to go where they went." -Will Rogers

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Hermiesguardian
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Re: Crabs always Underground?

Post by Hermiesguardian » Wed Aug 14, 2019 10:35 am

curlysister wrote:
Wed Aug 14, 2019 10:32 am
Oops...sorry HG, I was typing my reply at the same time you were replying!
:D that's ok.
raising son's dog, Dante. Husky/hound.
Raising daughter's hermit crabs, Shelder, Paras and Derek. Added 2 more of my own (of course) Pete and Stryper. Former mommy to 2 guinea pigs and beloved cat, Nissi

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Hermiesguardian
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Re: Crabs always Underground?

Post by Hermiesguardian » Wed Aug 14, 2019 10:39 am

Graz73 wrote:
Wed Aug 14, 2019 10:24 am
Thanks for all the tips. I'm sure they'll help at least a little!

What is defined as "Medium"? I'd guess these guys are roughly 2 inches square. Is that "small"? The other one we got from a pet store is a lot smaller. Maybe 1 inch.

Should I spray some dechlorinated saltwater or freshwater into the existing sand? (It is a pretty big mound, bigger than you described) I don't want to flood the crabs tunnels, but if the extra water is good for them, that might be an easy thing do do to help them.

The sand was previously "sandcastle" consistency but I'm sure it has dried out some since they've been buried in there.

I've got a thermometer. I can get a hygrometer, but don't have one. Any suggestions?

HG - Walmart or Lowes has good digital ones. A therm/hygro combined.

Also, how do I keep it humid enough in there? Just keep the lid sealed better? We've got a pretty good lid w few gaps.

HG - Seal the gaps. They will get enough oxygen when you feed them. Do ypu have a moss pit? Damp moss helps. And bubblers in the pools.

easiest source of calcium?

HG - Eggshells, crushed oyster shells, cuttlebone in bird section of petstore.

You're welcome.

Thanks again!
raising son's dog, Dante. Husky/hound.
Raising daughter's hermit crabs, Shelder, Paras and Derek. Added 2 more of my own (of course) Pete and Stryper. Former mommy to 2 guinea pigs and beloved cat, Nissi

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curlysister
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Location: Manitoba, Canada

Re: Crabs always Underground?

Post by curlysister » Wed Aug 14, 2019 12:33 pm

When you say shell-based sand, do you mean Calcium sand? Do you have a bag or box that it came in?

Also, a 'hill' isn't appropriate, substrate needs to be deep all over the tank. You can have a 'slope', but even at the most shallow area of the slope, it needs to be at least 6 inches. You can add a bit of dechlor fresh water along the edges, it will seep into the rest of the sub.
"If there are no dogs in Heaven, then when I die I want to go where they went." -Will Rogers


Topic author
Graz73
Posts: 5
Joined: Wed Aug 14, 2019 8:26 am
Location: OH

Re: Crabs always Underground?

Post by Graz73 » Wed Aug 14, 2019 12:52 pm

Thanks again everyone.
When you say shell-based sand, do you mean Calcium sand? Do you have a bag or box that it came in?

Also, a 'hill' isn't appropriate, substrate needs to be deep all over the tank. You can have a 'slope', but even at the most shallow area of the slope, it needs to be at least 6 inches. You can add a bit of dechlor fresh water along the edges, it will seep into the rest of the sub.

Right now We've got one end of the tank about 6 inches deep with beach sand and on top of that more of this "lizard/hermit crab" sand. Very whitish stuff that I believe was made from powdered shells. And, as I'm now learning, may not be the right stuff.

Anyway, this sandy mound slopes down toward the center of the tank with the play/rock/fake plants and leads to the two large water bowls and the area with the zoo-med coconut bedding on the other end of the tank.


Topic author
Graz73
Posts: 5
Joined: Wed Aug 14, 2019 8:26 am
Location: OH

Re: Crabs always Underground?

Post by Graz73 » Thu Aug 15, 2019 8:08 am

OK, I've put some of your recommendations to use already:

• Added some moss in the enclosure

• Adjusted the lid to fit better/tighter

• Wet down the sand for a better "sandcastle" consistency

• and was sure to get them some more fresh protein!


Topic author
Graz73
Posts: 5
Joined: Wed Aug 14, 2019 8:26 am
Location: OH

Re: Crabs always Underground?

Post by Graz73 » Fri Aug 30, 2019 3:20 pm

Hi Again.

• My enclosure is fairly sealed now and always has at least 80% humidity according to the digital hygrometer.
• I've been providing the crabs with lots of protein and other recommended foods.

and all of the other upgrades to their habitat previously mentioned
BUT
These crabs still wont come out of the ground. Even if I put my ear to the glass in the middle of the night I can rarely hear anything that might be them scratching around in there.

No "dead fish" smell, so that is good, but geez. Its been weeks or months since I've seen these things. And before that they were NEARLY always underground.

There aren't even any tunnels to the surface for them to come get the food anymore.

I'm pretty sure at least one is still alive under the sand, but this has gone on for months. So strange. Its like I've got an invisible pet.

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Hermiesguardian
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Re: Crabs always Underground?

Post by Hermiesguardian » Fri Aug 30, 2019 5:49 pm

It's called pet sand. Lol. Have you tried smoothing out the surface to see if there are footprints in the morning? Has it been longer than 4 months?
raising son's dog, Dante. Husky/hound.
Raising daughter's hermit crabs, Shelder, Paras and Derek. Added 2 more of my own (of course) Pete and Stryper. Former mommy to 2 guinea pigs and beloved cat, Nissi

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