Why don't humans have a mating season?

Why do the women gymnasts walk around between events with that goofy arm-swing gait?

Why are pandas' names doubled? Ling Ling, Tuan Tuan, Yuan Yuan….

Is it just me, or do all national anthems the world over, no matter how rich and exotic the culture, seem to sound like European marching-band music? Wouldn't one expect China's national anthem be more "plinky"? Shouldn't Iraq's national anthem sound a little more "Arab-y"?

Why do cockroaches flip over on their backsides when they die?

And the most perplexing, in my view….

Who made up the rule that if you wore a shirt all day, went home, and washed it, you can't wear it the next day?