PPS and a light crab

Question
Hi. I'm relatively new at keeping hermit crabs and I have a few questions.

First, one of my crabs are sort of burrowing, but I can still see his shell. I'm assuming it's PPS, but I'm worrying that he's not eating or drinking, as I always find him slightly burrowed in the same spot.

Second, when I picked up one of my other crabs, expecting the usual weight in my hand, he was lighter! I'm wondering what this is, and how to help my poor crab.

Lastly, what kind of food should I give them? I'm feeding them commercial hermit crab food and well washed, peeled carrots. I was wondering what to feed them to give them better nutrition.

Thanks, I know this is a lot to ask, but I appreciate it.

Answer
Dont' worry about the burrowing. If your crabitat humidity and temperature are between 74 and 82 the crab is just exhibiting normal behavior.

Do you offer salt and freshwater pools deep enough for them to get their shell opening into? They need to get water into their shells.

Go to www.hermitcrabcuisine.com for a great breakdown of foods.