MOVE-TO 期望输入是代理，但得到的是 NOBODY

我的代码所做的是设置一个内部灰色补丁区域和一个外部黑色补丁区域，海龟可以在其中繁殖（每个补丁上有一个）。一旦乌龟到达灰色和黑色区域之间的边界，我就会分配可变能量，以将乌龟的繁殖延迟一定的刻度（每个刻度能量增长一个单位）。当能量达到一定数量时，我希望海龟在一个空的黑色斑块中孵化新海龟，但是在黑色区域中第一代新海龟之后，我收到运行时错误“MOVE-TO 预期输入是代理，但得到了没有人代替。”

这是我的代码

breed [greens a-green]
breed [reds a-red]
greens-own[energy]

to setup
  clear-all
  ask patch 0 0 [ ask patches in-radius 15 [set pcolor 3]]
  ask n-of 20 patches with [pcolor = 3][sprout-greens 1 [set color green set energy 0]]
  ask n-of 20 patches with [pcolor = 3][sprout-reds 1 [set color red]]
  reset-ticks
end

to go
  division
  delay-expansion
  expansion
  tick
end

to division
ask greens[
    let empty-space neighbors with [pcolor = 3 and not any? turtles-here] ;crea un set llamado "empty-space" que son los patches negros q rodean a la celula verde y q no estan ocupados
    if any? empty-space [hatch 1 set color green move-to one-of empty-space] ; si existe algun patch negro alrededor, nace una celula verde y se ubica en ese patch
  ]

ask reds[
    let empty-space neighbors with [pcolor = 3 and not any? turtles-here] ;crea un set llamado "empty-space" que son los patches negros q rodean a la celula roja y q no estan ocupados
    if any? empty-space [hatch 1 set color red move-to one-of empty-space] ; si existe algun patch negro alrededor, nace una celula roja y se ubica en ese patch
  ]
end

to delay-expansion
  ask greens[
    let black-space neighbors with [pcolor = black and not any? turtles-here]
    if any? black-space [set energy (energy + 1 )]
  ]
end

to expansion
  ask greens[
    let black-space neighbors with [pcolor = black and not any? turtles-here]
    if energy > 5  [hatch 1 set color blue move-to one-of black-space]
  ]
end