What can I do?

[cafinator]

So I have an orange spotted blenny and a tribal blenny. My orange spotted blenny hides all the time and never comes out but very rarely. Just an hour ago was one of the rare times he does come out and the tribal blenny came down from his perch and darted toward the orange spotted. They were behind a rock so I couldn't see what actually happened but I saw the tribal dart toward the orange and then a lot of sand go everywhere...the orange spotted has no marks that I can see from his cave and he pokes his head out like he normally does everyone and then. Was this an attack or was he digging in the sand. What can I do to prevent this in the future if this was an attack