diff --git a/api.lua b/api.lua
index 4bb268c..1030095 100644
--- a/api.lua
+++ b/api.lua
@@ -1,5 +1,5 @@
 
--- Mobs Api (6th March 2017)
+-- Mobs Api (7th March 2017)
 
 mobs = {}
 mobs.mod = "redo"
@@ -850,28 +850,41 @@ end
 -- find and replace what mob is looking for (grass, wheat etc.)
 function replace(self, pos)
 
-	if self.replace_rate
-	and self.child == false
-	and random(1, self.replace_rate) == 1 then
+	if not self.replace_rate
+	or not self.replace_what
+	or self.child == true
+	or self.object:getvelocity().y ~= 0
+	or random(1, self.replace_rate) > 1 then
+		return
+	end
 
-		local pos = self.object:getpos()
+	local what, with, y_offset
 
-		pos.y = pos.y + self.replace_offset
+	if type(self.replace_what[1]) == "table" then
+
+		local num = random(#self.replace_what)
+
+		what = self.replace_what[num][1] or ""
+		with = self.replace_what[num][2] or ""
+		y_offset = self.replace_what[num][3] or 0
+	else
+		what = self.replace_what
+		with = self.replace_with or ""
+		y_offset = self.replace_offset or 0
+	end
+
+	pos.y = pos.y + y_offset
+
+	if #minetest.find_nodes_in_area(pos, pos, what) > 0 then
 
 -- print ("replace node = ".. minetest.get_node(pos).name, pos.y)
 
-		if self.replace_what
-		and self.replace_with
-		and self.object:getvelocity().y == 0
-		and #minetest.find_nodes_in_area(pos, pos, self.replace_what) > 0 then
+		minetest.set_node(pos, {name = with})
 
-			minetest.set_node(pos, {name = self.replace_with})
-
-			-- when cow/sheep eats grass, replace wool and milk
-			if self.gotten == true then
-				self.gotten = false
-				self.object:set_properties(self)
-			end
+		-- when cow/sheep eats grass, replace wool and milk
+		if self.gotten == true then
+			self.gotten = false
+			self.object:set_properties(self)
 		end
 	end
 end
diff --git a/api.txt b/api.txt
index d945f42..fac6ed5 100644
--- a/api.txt
+++ b/api.txt
@@ -1,5 +1,5 @@
 
-MOB API (6th March 2017)
+MOB API (7th March 2017)
 
 The mob api is a function that can be called on by other mods to add new animals or monsters into minetest.
 
@@ -102,11 +102,18 @@ This functions registers a new mob as a Minetest entity.
             'jump' sound when jumping
             'explode' sound when exploding
             'distance' maximum distance sounds are heard from (default is 10)
+
+Mobs can look for specific nodes as they walk and replace them to mimic eating
+
         'replace_what' group if items to replace e.g. {"farming:wheat_8", "farming:carrot_8"}
         'replace_with' replace with what e.g. "air" or in chickens case "mobs:egg"
         'replace_rate' how random should the replace rate be (typically 10)
         'replace_offset' +/- value to check specific node to replace
 
+The 'replace_what' has been updated to use tables for what, with and y_offset e.g.
+
+   replace_what = { {"group:grass", "air", 0}, {"default:dirt_with_grass", "default:dirt", -1} }
+
 Mob animation comes in three parts, start_frame, end_frame and frame_speed which
 can be added to the mob definition under pre-defined mob animation names like: