missing crabs

[Shy_Koi]

I just caught my skunk cleaner shrimp red handed yesterday.
Have had the same 8 hermit crabs (blueleg and scarlet mix) for the past year and noticed that most were mia lately, with just their empty shells on the sandbed.

Went to feed the tank yesterday a.m., and saw my cleaner shrimp with what I thought was a hermit crab molt, but the molt was waving it's claws at the shrimp!

I've had this cleaner shrimp for over a year, and it gets target fed daily with mysis, krill, flake and/or pellet.

Not sure what to think??? Hopefully it was an isolated incident, and the unfortunate crab was simply caught during a molt...

~Tamara