Human.

During a lecture, the lecturer asked us an interesting question,

"What's the different between an animal & a human?"

The students were put into silence. Maybe some of them are thinking, maybe some are blanked out (this one is me).

As for me, the answer spurt out by my lecturer seems interesting.

"Humans, referring to a philosopher, who I forgot his name, are animals which always in questions. They always ask questions."

...

Yeah, he was right. Human have the ability to think, so it is not possible to humans to always wonders what's what, how's how, & the why's.

Then the lecturer asked, "Any questions?"

We were put into silence, again.

"Seems that I'm facing with non-human here, weren't I?"

We just gave a grimace among ourselves.