Crab sitting in food bowl / solo crab tank

[Tides]

Hi all,

As a class pet I purchased hermit crabs about 6 months ago. I had no idea that they were wild caught and, from the guidance of my local pet shop, bought a tank which was far too small. One crab sadly died the next day and I researched everything I could about hermit crabs. I bought two larger tanks, one for my classroom and one for my home, to try and house these poor guys in the right conditions. I ended up housing my two small crabs in the classroom tank and the really big boy in the separate tank at home. I have a holiday plan and an interim tank too. But I have a few questions for you experts, if you're able to respond (have read so many conflicting things online so would love some advice) -

1. One of my classroom crabs appears very truamtised. Very rarely moves when he sees shadows. He withdraws frequently and I've noticed he sits in his food bowl a lot. When he was in the small tank before I switched them, he also sat on the food bowl. It seems to be a safe place for him. Should I make this bowl more of a safe place and add a new food bowl? Maybe make it a bath or a moss bath? Any help would be appreciated because I think he's very stressed and don't want to die from PPDS.

2. My big boy, who is about the body length of a man's thumb, was too big at the pet store and had been there for months. Whether it was a line or not, I was sympathetically encouraged to house him. Anyway, now he's in a big tank sllo at my place. He's very active and loves attention and reacts positively to my voice. I hide little treats, give him enrichment, and change the tank set up ever few months to give him new things to climb/explore. He's super active and moves around during the day and night. Anyway - I know crabs are social creatures. I'm hesitant to introduce him into a bigger tank with other crabs because he seems to withdraw and hide for days on end (tested last school holidays and he was not a fan of the two significantly smaller crabs). Has anyone had a solitary crab? My only thought might that be they are social in the wild but in containment it's another story. Could he be happy being solo?

Thank you all fof any feedback - really appreciated.

[curlysister]

Welcome to crabbing!
Do your classroom crabs have lots of places in the tank to hide? They will feel safer if they have lots of places to hide from the world, and you may actually see them out more because they can get to a hiding place really quickly if they feel they need to.

What used to be thought of as 'social' behaviour, is actually now known to be a lot of 'resource sharing'. So crabs will be found in groups where the resources are plentiful. Many crabs have done just fine on their own in captivity, because we provide the resources they need.