     names = {}
     @visitThings(
       (t) ->
-        n = names[t.type] ||= t.typeName()
-        counts[n] ||= 0
+        n = names[t.type] ?= t.typeName()
+        counts[n] ?= 0
         counts[n] += 1
       false, true
     )

    super()
    @hr = null
  healthRatio: ->
    @hr ||= @hp / @health()

class Plant extends Organism
  constructor: ( location, options = {} ) ->

class Organism extends Thing
  constructor: ( location, options = {} ) ->
    super location, options
    @genes      ?= @defaultGenes()
    @hp         ?= @health() / 2
    @generation ?= 1
    @radius = options.radius || 5
    @tick   = @universe.tick
    @babies = 0
