   # the steps involved in one go of the universe's clock
   go: ->
     @timer ||= new Date()
-    unless @dead
+    unless @dead || !@change
+      @change = false
       @goTime = new Date()
       @tick += 1
       self = @

    nextThing()
  remThing: (thing) ->
    thing.dead = true
    for v in ( thing.marges || [] )
      @geoPool.push v
    for k, v of thing.others when v

  # how much you get for free per round
  gain: -> 0
  react: ->
    start = @hp
    @hp += @gain()
    @hp -= @need()
    @hp = Math.min @hp, @health()
    @universe.change = true if start != @hp
  # number of times per baby that one can attempt to find it a cradle
  babyTries: -> @genes.babyTries[0]
  # number of health points to transfer to baby
