The clip shows two blue-striped hermit crabs in one of the mangrove pools (former prawn pond).
These crabs were both in Rodong snail shells. I was alerted to some house-swapping action by a knocking sound. One crab was tapping or knocking onto the other shell which was occupied by the other crab.
The loser was cajoled out of its shell by the aggressor and it ran out beyond the reach of the aggressor who promptly assessed the now empty shell. Finding it suitable, it climbed into the 'new' shell leaving its own free for the loser to lay claim to it. The victor's former shell now empty was free for the loser to occupy which it did without much hesitation. Any protection was better than none and hermit crabs cannot afford to be 'naked' i.e. without a hard shell because their bodies are naturally unprotected and soft.
With both crabs swapping shells, they quickly parted ways. Perhaps they may meet again on the other side of the mangrove pool ... and another battle may present itself. What a great way to recycle one's home!
Find out more about these and other Singapore hermit crabs here :