A scorpion and a fox were both waiting by a river.
The scorpion turned to the fox and asked — "I cannot swim, will you carry me to the other side of the river?"
The fox was hesitant — "I can't because you'll sting me."
"If I sting you, we'll both drown" — Replied the scorpion
This argument was sensible to the fox so he allowed the scorpion to sit on top of his head as he carried him across the river.
About halfway across, the scorpion stung the fox, injecting his lethal poison into the animal.
Already growing weak, the fox looked up at the scorpion — "why did you do that? Now we're both going to die."
The scorpion shrugged — "Because I'm a scorpion. It's in my nature."