what is the difference between animals and humans?

what is the difference between animals and humans? somewhere, sometime i'd come across the idea that it could well lie in the human ability to imagine and engage with death. it sort of resurfaced and i can't stop obsessing.
not the ability to imagine and create love - well some animals can do that, not the ability to imagine and recreate sunsets - some primates can paint, not the ability to embrace and live life - every organism does so; but to think about the the cessation of life, to be able to imagine what death is and to arrange life around the absence of life - that is being human!
i'm seriously thinking of sending a chain mail to all the entries in my address book and ask people what they think could the actual difference be. for this, surely, can't be it. can it?

christmas heartbreaks. deja vou? perhaps. tired.
it seems like the right to remain clueless comes with a shelflife. and the best by date is coming perilously close.
light a candle for me and send a stinking rich marwari lover my way ye gods.
but on the sunny side, i got a towel and a kitkat for christmas.