When taking a second to give the rocks a close look I noticed a small 1/3 inch round black spot with a pattern of white dots. I touched it with something to see if it retracted into the rock and it di nothing. A few seconds later the center of it raised up making it into a cone shape and it started moving. I took a picture but it is not a good on. You can see it in the top left quarter of the picture. Does anyone have a clue of what it is??

