Killing in a dream means great emotional pain.

Dreaming of killing someone means that the dreamer is experiencing several emotional pressures; Dreaming that you are a witness to a killing scene means that a change that you don't like very much is about to happen; Dreaming that other people kill insects or other animals means that the dreamer will receive help like friends from others; Dreaming of killing insects or other animals means that the dreamer has overcome some obstacle through his own efforts.