Will clownfish dancing alter tank?

[NicPeg]

Strange question here. My clownfish have been dancing alot. I have a small 9 gal. tank and they always dance in the same corner under the anemone. I'm wondering if them dancing so much and moving the sand around could cause the rocks to collapse? Should I push the sand back into the area or just let them continue?. Here is a picture of what it looks like right now.

 

[NicPeg]

 

[NicPeg]