i had one of these guys too ( a red oscar ) his name was rusty. he lived for 12 years! he was cute when he wasnt ripping goldfish to shreds or slamming into the glass because he didn't like my mom in the room. he could do tricks.
hmm i'm not sure if they do they. they probably would if anyone actually left the tank uncovered (which would be mean since they need a hood with direct light at least like 6 hours a day). but mine used to hit the lid to open it if he was hungry.