Only they're not your traditional shell shape.
There are cityscapes, mansions and even a trio of windmills.
The imaginative little creations are the work of Japanese artist, Aki Inomata, and together form a project entitled: 'Why Not Hand Over a "Shelter" to Hermit Crabs?'
Inomata explains the thinking behind her work on her website:
"In this piece I gave hermit crabs shelters that I had made for them, and if they liked my shelters, I got them to use them as their shell.
"I overheard that the land of the former French Embassy in Japan had been French until October 2009; that it was to become Japanese for the following fifty years, and then be returned to France. This concept made me think of hermit crabs, which change their shells.
"The same piece of land is peacefully transferred from one country to the other. These kinds of things take place without our being aware of it. On the other hand, similar events are not unrelated to us as individuals. For example acquiring nationality, moving, and migration.
"The hermit crabs wearing the shelters I built for them, which imitate the architecture of various countries, appeared to be crossing various national borders. Though the body of the hermit crab is the same, according to the shell it is wearing, its appearance changes completely. It’s as if they were asking, “Who are you?”"
Limited edition versions are available to buy from Tokyo's Ai Kowada Gallery.