   # 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

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

    @setAttributes options
    @others = {}
    uni = @universe
    uni.change = true
    [ @x, @y ] = location
    @velocity = [ 0, 0 ]
    @radius ||= 5
