Shrimp under trachy

[jasonrusso]

I caught my pistol shrimp tunneling under my trachy today. I suspected this was happening but I never saw it. Sometimes he puts sand on the trachy which makes it blow up like a ball.

There really isn't much I can do, but is this necessarily harmful to the trachy? The trachy and goby literally have 8 other caves (they are all connected, little engineers). This is just one of them.