What is this behavior in my decorator crab?

[Sierra_Bravo]

I had seen this exact same thing with my decorator crab and it was a bit...disturbing...to watch the carapace open and it dig around in there. The author of the video thought it was removing babies or grooming. What I assume are gills were blood red in mine, so I'm leaning towards it was cleaning its gills.

Do all crabs do this? I had never seen this before.

 

[Justin poirier]

I'm saying cleaning because he or she is eating whatever is in there. Doubt it would eat her babies

 

[justin.k.nelson]

so weird