Hermit Crabs

I know this is not an individual spotting, but it was so bizzare I thought it might be appreciated. During the day this lawn was bare green sandy lawn near the beach. At night little shuffles in the leaf litter in the surrounding bush, from under the house, from down the drive, and from down the footpath to the beach (check the little trails of dozens of hermits having climbed the stairs from the beach). It was like this all night, all over the lawn, hermits coming and going and having little conferences. I thought maybe it was some kind of mating event, or maybe some kind of 'shell swap met'... or something, not sure what. I thought it was quite amazing.