stuffing her face with oyster shell

[youdunnojack]

hello friends,
i'd like to give a little back story before just asking my question. i personally bought two hermit crabs from an awful beach shop almost exactly a year ago. i had no idea of the horrors of the industry and thought they'd make an interesting and unique pet (which is true, but i would have preferred to adopt some from someone near me in hindsight). i had no intentions of keeping them in the ridiculous "critter keeper" box of course, but i will admit that i didn't know quite the level of care they required. got back home and the first day back i got them a basic setup and have been upgrading that setup basically since then. i've done literally hours and hours of research and video watching to try and provide them the best environment possible since they were ripped from their homes and believe it to be as ideal now as it can be. eventually i'd like a bigger tank, but the 20 gallon long has been fine for the size of my crab(s). the medium sized crab didn't survive adjusting to the new environment and passed within a month, but the little guy (tiny tom) did. i was on the lookout for another small crab or two to adopt since then because of the social nature of hermits. that day finally came when part of my family returned from a beach trip and my little sister (she is 9 years old) had bought two crabs in the classic critter keeper. i informed her and my parents of the care they needed and they just gave them to me instead of putting in all that effort and money themselves. this was about two months ago. i put them in with tiny tom asap and one of them did a little exploring (mostly hiding), and literally two days in, she dug down into the sand. i thought she was for sure trying to de stress. she wasn't seen again for a little over a month. tiny tom and the other new crab started hanging out together and climbing over the cork bark and inside of the hollow cork log together. oddly enough, they were both very active during the day. literally the same day or maybe a day apart, probably two weeks after the new girl had dug herself down, they both went under the cork bark and assumingly created their own tunnels and are molting. haven't seen tiny tom or the other new guy since. the new girl i named harriet just resurfaced a little less than two weeks ago. she was going crazy eating a lot and i did pick her up once to see if she had definitely molted and she certainly had. since then i've let her be as i don't want any extra stress on the crabs. aside from the day she came up, she has been the typical night walker. she would come out almost like clock work when the automatic light timer shut off and would be doing various things when i would check on her (i have a camera to help me monitor them). thursday morning this past week, i saw her climbing on the little rope bridge type decoration and watched her for a little while. she climbed to the underside of the bridge and was hanging on like a monkey until she fell. it is a very short distance, the highest point of the bridge is probably 5 or 6 inches off the ground and where it looked like she fell would've been closer to 4 inches max. anyway, it wasn't a nice cushion below, it was one of the shell piles that are in the tank. she got up right away and looked around and shortly after returned to her spot she's created under a different piece of cork bark from the two who are still gone. since that fateful night, she still comes out basically within a half hour of the lights going out. however, she has been crawling almost directly over to the powdered oyster shell dish and she sits there and i'll check again in the morning when the lights are still off (i get up early early) and she will almost be in the exact same spot on the dish. then she senses the lights will be back on like an hour before they come on and goes back to her spot under the cork bark. friday i caught her do a tiny little toe dip in the freshwater or saltwater pool right before returning to the cork. i am very sorry for the lengthy post, just wanted to give some kind of background so it wasn't just a question with no context. i say all that to ask this: is this normal crab behavior? is she just using the calcium to help harden her exoskeleton after molting? or is it possible that the short fall injured her and she's now lethargic and trying to eat that to heal in some way? i couldn't find any posts similar enough to go off of so i have created my own. just want to make sure she's okay while she's waiting for her two brothers to resurface. thanks for any help!

[curlysister]

Welcome to crabbing and to the site!
She will not have injured herself with that little fall.
Sometimes crabs are more active than other times. And eating more calcium after a molt can be normal too.
Nothing you are describing sounds worrisome to me.

[youdunnojack]

thank you for welcoming me and thank you for taking the time to read and respond! and that's great news, i just wanted to make sure as i am still relatively new to the crab world