scorpions and snakes, 

lions, tigers, crocodiles, jackals 

harmful bacteria, virus 

--all part of nature's creation, 

along with elephants, cows, goats, parrots, 

butterflies and roses each has a role of its own 

so also a wide range of models exist in the human beings, greatest, to the worst, being  products of the same nature.

wise man will be careful not to be a prey to the bad, 

knowing that a snake bites, 

but he cannot eliminate the specie by killing one or two .

 however nature has made some to vanish  

and evolved some others by its own mechanism.