Ill behaved black, ghost, knife fish

Hi everyone,

I think I have a little problem with my BGKF.
He is an avid eater and spends ALL his time hunting for anything edible.....quite natural
However, recently I think he has been nibbling away at the silicon sealant in the corners of the tank. :shock:
Does anyone have any knowledge about these fish? and has anyone heard of them gnawing enough silicon to cause real problems with the tank?

Vbrgds
Duckle-bum

 

My guy is a little too shy for that, I think...

But I once read about an oscar nibbling at the stuff. It shouldn't really be coming off in t he first place. I think I read to use a razor blade to cut the loose edges and he bite the fastened adhesive.