Can you imagine a world where the rich people who need a new home,will abandon their home and they pass it down to the not so wealthy people. Then they pass down their old home down the line and so on.
It seems impossible right?
These hermit crabs are doing exactly that. When they new shells,they line up from biggest to smallest and when the biggest starts to move into a new,bigger shell it ignites a chain reaction. Everybody will move one spot up in the home exchange line.
The reason why this might be possible is that these crabs can’t survive the tropical sun for a long period,that is why they need to move shells quickly.