diff --git a/plugins/lua/autobutcher/nestboxesEvent.lua b/plugins/lua/autobutcher/nestboxesEvent.lua
index ca353a801c6..1a1a587e787 100644
--- a/plugins/lua/autobutcher/nestboxesEvent.lua
+++ b/plugins/lua/autobutcher/nestboxesEvent.lua
@@ -5,85 +5,11 @@ local printLocal = nestboxesCommon.printLocal
 local printDetails = nestboxesCommon.printDetails
 local utils = require('utils')
 ---------------------------------------------------------------------------------------------------
-local function copyEggFields(source_egg, target_egg)
-  printDetails('start copyEggFields')
-  target_egg.incubation_counter = source_egg.incubation_counter
-  target_egg.egg_flags = utils.clone(source_egg.egg_flags)
-  target_egg.hatchling_flags1 = utils.clone(source_egg.hatchling_flags1)
-  target_egg.hatchling_flags2 = utils.clone(source_egg.hatchling_flags2)
-  target_egg.hatchling_flags3 = utils.clone(source_egg.hatchling_flags3)
-  target_egg.hatchling_flags4 = utils.clone(source_egg.hatchling_flags4)
-  target_egg.hatchling_training_level = source_egg.hatchling_training_level
-  target_egg.hatchling_mother_id = source_egg.hatchling_mother_id
-  target_egg.mother_hf = source_egg.mother_hf
-  target_egg.father_hf = source_egg.mother_hf
-  target_egg.mothers_caste = source_egg.mothers_caste
-  target_egg.fathers_caste = source_egg.fathers_caste
-
-  local mothers_genes = df.unit_genes:new()
-  mothers_genes.appearance:assign(source_egg.mothers_genes.appearance)
-  mothers_genes.colors:assign(source_egg.mothers_genes.colors)
-
-  local fathers_genes  = df.unit_genes:new()
-  fathers_genes.appearance:assign(source_egg.fathers_genes.appearance)
-  fathers_genes.colors:assign(source_egg.fathers_genes.colors)
-
-  target_egg.mothers_genes = mothers_genes
-  target_egg.fathers_genes = fathers_genes
-  printDetails("mothers_genes fathers_genes done")
-
-  target_egg.hatchling_civ_id = source_egg.hatchling_civ_id
-  printDetails('hatchling_civ_id done')
-  printDetails('end copyEggFields')
-end --copyEggFields
----------------------------------------------------------------------------------------------------
-local function resizeEggStack(egg_stack, new_stack_size)
-  printDetails('start resizeEggStack')
-  egg_stack.stack_size = new_stack_size
-  --TODO check if weight or size need adjustment
-  printDetails('end resizeEggStack')
-end --resizeEggStack
----------------------------------------------------------------------------------------------------
-local function createNewEggStack(original_eggs, new_stack_count)
-  printDetails('start createNewEggStack')
-  printDetails('about to create new egg stack')
-  printDetails(('type= %s'):format(original_eggs:getType()))
-  printDetails(('creature= %s'):format(original_eggs.race))
-  printDetails(('caste= %s '):format(original_eggs.caste))
-  printDetails(('stack size for new eggs = %s '):format(new_stack_count))
-
-  local created_items =
-  dfhack.items.createItem(
-    df.unit.find(original_eggs.hatchling_mother_id),
-    original_eggs:getType(),
-    -1,
-    original_eggs.race,
-    original_eggs.caste
-  )
-  printDetails('created new egg stack')
-  local created_egg_stack = created_items[0] or created_items[1]
-  printDetails(df.creature_raw.find(created_egg_stack.race).creature_id)
-  printDetails('about to copy fields from orginal eggs')
-  copyEggFields(original_eggs, created_egg_stack)
-
-  printDetails('about to resize new egg stack')
-  resizeEggStack(created_egg_stack, new_stack_count)
-
-  printDetails('about to move new stack to nestbox')
-  if dfhack.items.moveToBuilding(created_egg_stack, dfhack.items.getHolderBuilding(original_eggs)) then
-    printDetails('moved new egg stack to nestbox')
-  else
-    printLocal('move of separated eggs to nestbox failed')
-  end
-  printDetails('end createNewEggStack')
-end --createNewEggStack
----------------------------------------------------------------------------------------------------
 local function splitEggStack(source_egg_stack, to_be_left_in_source_stack)
   printDetails('start splitEggStack')
   local egg_count_in_new_stack_size = source_egg_stack.stack_size - to_be_left_in_source_stack
   if egg_count_in_new_stack_size > 0 then
-    createNewEggStack(source_egg_stack, egg_count_in_new_stack_size)
-    resizeEggStack(source_egg_stack, to_be_left_in_source_stack)
+    source_egg_stack:splitStack(egg_count_in_new_stack_size, true)
   else
     printDetails('nothing to do, wrong egg_count_in_new_stack_size')
   end