Strawberry crabs (Coenobita perlatus)
"Coenobita perlatus are found living near coastal shorelines. Coenobita perlatus require regular access to the sea or water of high salinity. They are never far from shore or adjacent dunes, and have been found in tidal pools, sandy areas, and humid areas with dune vegetation."
"Coconut crabs are definitely strong and you really don't want one to get hold of you, but they are also typically quite shy. It's the little baseball-sized Strawberry Hermit crabs that will come after you. Their claws are tiny and they can only pinch out a little chunk of you, but they can be quite aggressive and they often show up in gangs of a hundred or more. While we were eating lunch at the Seven Site we had to watch where we stepped because the ground was typically almost covered with Strawberry Hermits. They'd climb up your boots and right up your pants leg if you let them."