**EXPLANATION**<BR/>

 - Bhisma laid in Bed Of Arrows due to his Bad karma in his past lives by **Piercing a Butterfly**.
 - As he pierced the **[Butterfly][1]** In Return he got **Pierced by Arrows**.
 - Bad Karma for **[Killing a Insect][2]** is Less when compared to harming a Human. 
 - Bhisma was a **Bramacharya,Great Warrior,Dharma Follower** and would had **Good Karmas in Great Level**.<br/>

**QUESTION :**

 - If Bad Karma for Killing a Insect is Very Small then how a Great Dharma person like Bhisma would be Affected by Bed of Arrows ?

 - Why Insects Killing are compared to be Less as compared to humans ?


  [1]: http://hinduism.stackexchange.com/questions/15698/a-question-about-blood-sacrificial-acts-in-hinduism/15713#15713
  [2]: http://hinduism.stackexchange.com/questions/9175/is-it-wise-to-kill-an-insect-just-because-it-is-bothering-you