"""

Engulf is simulation containing:

* Subjects who need to:
  * eat
    * low energy ground stuff
    * other alive subjects
    * other dead subjects
  * sleep
  * want to be not alone
    * with non aggressive subjects
  * want to be alone
  * reproduce
    * with non aggressive subjects
    * and transmit tendencies because their cultures can be
      * eat: - eat background stuff, + eat subjects
      * alone/not alone: - be alone + not alone

"""