J told me all about coconut crabs the other day (I had never heard of them to be quite honest).
I went looking on the web for info and sure enough there they were. They say they can climb up coconut trees and knock the coconuts onto rocks below to get them open. They also eat birds!
I then remembered the Christmas Island crab migrations, so we watched some documentaries on these also.
There are plenty more Arthropods to discover!