Hermit crab acting strange

[BelleMorte]

I put in some new shells for my hermit crab that I have had for last two years and me and my husband had a good laugh watching him climb in and out of them and his old shell. I noticed the last few days that he has picked one and hasn't moved at all from the shell or the spot. Every now and again I see his legs poke out and then he goes back into the shell. I he getting ready to molt or should I start to worry?

 

[Flreefer]

I've watched this too, it's pretty funny!! So much anticipation for the final jump.
He could just be tidying up his new abode. Sometimes too, they will pick a shell that's hard for them to move. Possibly put a few slightly smaller shells near him, in case he wants to transfer again.
If you still see that he's active, he should be fine.

 

[BelleMorte]

I have multiple sizes of shells that I picked up off a couple beaches while in new Zealand when I was a teenager and some from when my son had a couple of hermit crabs from romancing the stone. This was just a behavior I hadn't seen from him before when he switched shells so I was starting to get worried