Fish acting very strangely for a few seconds

So the other day I was walking by my tank and I saw my File Fish going balistic. Darting back and forth, up and down, at a lightning speed. Almost like he was receiving an electric shock of some sort or epileptic seizure. After a few seconds of this he took off behind some LR. What could this have been? Has anyone else experienced this reaction. He is an Aptasia eating File Fish and I'm wondering if he ate something nasty and was reacting in a panic mode.

 

sometimes when fish see their reflection in the glass they get all territorial, if he does it often then i would start to worry.

 

Makes sense. He seems fine now.

 

You probably startled him. I have a stuuuuupid fish on one of my tanks. Sometimes when I walk into the room he gets startled jumps up out of the water, rebounds off the lights and back into the tank with a shower of scales following. The big dope just gets caught by surprise and spaz's out.

 

Yea I'm sure he's ok, my fish do it from time to time