The Sting of Stonefish

I like to spend most of my leisure time in the seashore. Though being there is not just for enjoyment but it is also a good place where we could get food. One day, my friend and I went there gathering shells for the dinner. Aside from collecting shells, we were also catching fish. As we were there, we're very noisy catching and chasing fish. Doing such thing, we used to bare foot. During that time, we were laughing out loud while chasing the fish until my friend stepped on something. It's a stone fish yet we did not recognize it because it looked like a stone. A matter of seconds, the sting scattered up to her thigh. Her foot swelled and she could hardly walk. The following day, the pain subsided. From then on, I no longer step on the seashore without clearing it.