I think my piranha is retarded

[joepythons]

I have an oscar that runs into the side of the tank when the lights first go on. I’ve figured out that he/she is fighting his/her reflection; this may be the case with your piranha.

Not in this case .He does it lights on or off and he is not chasing a goldfish and missing lol.

This reminds me of that windex commercial with the 2 birds sitting outside the house and the lady is cleaning the sliding door with the windex, they swoop down and smash into the door
Seriously though have you tried putting something opaque on the sides of the tank like black construction paper etc.?

He slams into all 4 sides and flies into the top.Thank god the lid is covered or he would fly out