im not takin any, but i mean... fish usually jump out of tanks or places which are uncomfortable... doesnt this have sth to do with them trying to get out? its just a theory though
Sorry to hear that, I had that happen with an african butterfly once (I know, not as bad as an arro, but he was one of my faves at the time). He actually almost made it into the tank 2.5 feet away with no cover on it.