PLEASE HELP HERMIT CRAB OWNERS!?

Without knowing the history of the hermit crabs, or their current tank conditions, it's difficult to pin-point exactly what could be the matter.

The diet you are feeding is sufficient - that is, better than commercial hermit crab food. But I'd suggest adding a source of calcium (cuttlebone, egg shells, etc.) and possibly more protein (any cooked, uneasoned meats, including eggs), and possibly cut back on the Cheerios as they contain sugars (which aren't too great for crabs).

Hermit crabs need a humidity level of at least 70%, so I'd try to boost that if possible. My best suggestion is to add a moss pit, if you don't have one already, and cover the top of the tank with plastic wrap (leaving a little open space for air flow, but not enough to let out too much humidity).

Do you have substrate (play sand is the most recommended substrate for hermit crabs) at the consistency of a sand castle, deep enough for the crabs to burrow if they so desire (a few inches taller than your largest crab)? If a crab doesn't have enough substrate (or in some cases, even if they do), they will surface molt (extra care needs to be taken if this is the case).

Have the crabs (especially the one in question) molted at all since you had them? If not, PPS (Post Purchase Syndrome) may still be a threat. Some think after the first month or so the threat of PPS is eliminated, whereas others think it's only after the first molt that the threat of PPS is eliminated.

The crab can be in a pre-molt phase, at which point they will become lethargic and possibly quit eating. The problem is, PPS has very similar symptoms, so it's difficult to pin-point. So it may very well be a waiting game.

If the other crab is not bothering him, I'd suggest leaving him alone and possibly placing a hide over him. Continue offering fresh and salt water along with protein and calcium-rich foods (honey and crushed oyster shells are usually a good start).

Edit:

Realized I didn't mention heat. Hermit crabs should have access to a heat gradient (from lower to mid-70s, to upper to low-80s) within their crabitat. Fluctuation in (or inadequate) temperatures could result in a crab becoming lethargic.

1) Your humidity is too low. They need at least 70% and some species need 80%. They have modified gills, not lungs and so need very humid air to breathe. Without high enough humidity, their gills slowly dry out. As they don't repair their gills when they molt, this is fatal and they die very slowly and painfully.

2.)Don't feed them any processed food like wheat thins or cheerios. The additives, preservatives and added table salt are not good for them. Prolonged exposure will kill them. There is a full list of safe foods here http://www.hermitcrabassociation.com/phpBB/viewtop...

(I suggest you check out the rest of that site too. It's a forum for hermit crab owners and you'll get a lot of useful info there. We don't mind people asking us lots of questions.)

Has Herman molted before? Different crabs have different pre-molt behavior. Some will simply vanish into the sand and others will mope around for days looking very lethargic and then dig down.

Don't hesitate to ask more questions on that forum I linked, or you can email me.

what stupid names for crabs....

did you check to see if he's alive?