Zebra Tail Blenny took a trip to the refugium

I noticed that I could not find my zebra tail blenny in the main tank, but thought nothing of it since several things in the tank seem to hide then show up later.  Well, later that night it was sitting in my refugium.  I still wonder how it made it all the way down there.  Since then I installed the filter sponge that is behind the overflow to prevent stuff like that happening.  Just really interesting find.  Now to capture him and move him back to the main tank.