Fish on fish violence?

For about a month, my two fancy percula clowns (who came first) and my lawnmower blenny have been getting along just fine. The last couple of days, though, I've noticed the blenny getting more and more aggressive toward the clowns. I was of the impression blennies were peaceful. Was I wrong?

 

The clowns are probably encroaching on an area that the blenny has staked out as a home or feeding territory. Any fish can become strongly territorial.

 

Is it a stary blenny? They can get aggressive.

 

It's a lawnmower blenny. And before this, he mostly hung out in the live rock in the lower left of my tank, while the clowns appear to be "hosting" the powerhead in the upper right. Now the blenny is going up there periodically to bother them.

 

Sounds like dominance issues should work out in a week or two.

 

I've heard of lawnmower blennies turning very aggressive. Let it go for a few weeks and see what happens, but if it doesn't get better, or gets worse, I would remove it.

 

the lawn mower blenny is the boss of my tank, but thats probably because he is twice as big as the other fish.