The Shell Exchange

Pip is a small hermit crab. His shell is too small. His legs stick out. A gull walks on the rocks. Pip is afraid. On the sand there is a big shell. It is too big for Pip. He waits. A big old crab comes. She likes the big shell and leaves her old shell. Then the crabs make a line, from big to small. Each crab takes the shell of the next one. At last a shell fits Pip. He is safe!