The Halloween Hermit Crab is widely distributed in the Indo-West Pacific including the Red Sea, Reunion, Mauritius, West coast of India, Sri Lanka, Christmas Island, Cocos Keeling Islands, NW Australian coast, Vietnam, Indonesia, Taiwan, South Japan, Philippines, Northern Mariana and Guam, Papua New Guinea, East Australia, Chesterfields, New Caledonia, Vanuatu, Fiji, American Samoa, Niue, Hawaii, French Polynesia.
Hermit crabs have soft bodies and do not grow their own shells, so they use the empty shells made and left behind by other animals, like snails.
Hermit crabs are considered ecosystem engineers since they change their habitat by using discarded shells.