diff --git a/nssm_api.lua b/nssm_api.lua
index 0a788a2..9e73b9c 100644
--- a/nssm_api.lua
+++ b/nssm_api.lua
@@ -208,7 +208,8 @@ function digging_ability(
 	max_vel,	--max velocity of the mob
 	dim 		--vector representing the dimensions of the mob
 	)
-	if math.random(1,100) < nssm:virulence(self) then return end
+
+	if math.random(1,nssm:virulence(self)) ~= 1 then return end
 
 	local v = self.object:getvelocity()
 	local pos = self.object:getpos()
@@ -252,12 +253,12 @@ function digging_ability(
 				local n = minetest.env:get_node(p).name
 				--local up = {x=pos.x+dx, y=pos.y+dy, z=pos.z+dz}
 				if group == nil then
-					if minetest.get_item_group(n, "unbreakable") == 1 or minetest.is_protected(p, "") or not nssm:affectbones(self) then
+					if minetest.get_item_group(n, "unbreakable") == 1 or minetest.is_protected(p, "") or (n == "bones:bones" and not nssm:affectbones(self) ) then
 					else
 						minetest.env:set_node(p, {name="air"})
 					end
 				else
-					if (minetest.get_item_group(n, group)==1) and (minetest.get_item_group(n, "unbreakable") ~= 1) and not (minetest.is_protected(p, "")) then
+					if (minetest.get_item_group(n, group)==1) and (minetest.get_item_group(n, "unbreakable") ~= 1) and (n == "bones:bones" and not (minetest.is_protected(p, "")) ) then
 						minetest.env:set_node(p, {name="air"})
 					end
 				end
@@ -272,7 +273,7 @@ function putting_ability(		--puts under the mob the block defined as 'p_block'
 	p_block, 	--definition of the block to use
 	max_vel	--max velocity of the mob
 	)
-	if math.random(1,100) < nssm:virulence(self) then return end
+	if math.random(1,nssm:virulence(self)) ~= 1 then return end
 
 	local v = self.object:getvelocity()
 
@@ -299,10 +300,10 @@ function putting_ability(		--puts under the mob the block defined as 'p_block'
 	pos1 = {x = pos.x+dx, y = pos.y, z = pos.z+dz}
 	local n = minetest.env:get_node(pos).name
 	local n1 = minetest.env:get_node(pos1).name
-	if n~=p_block and not minetest.is_protected(pos, "") and nssm:affectbones(self) then
+	if n~=p_block and not minetest.is_protected(pos, "") and (n == "bones:bones" and nssm:affectbones(self) ) then
 		minetest.env:set_node(pos, {name=p_block})
 	end
-	if n1~=p_block and not minetest.is_protected(pos1, "") and nssm:affectbones(self) then
+	if n1~=p_block and not minetest.is_protected(pos1, "") and (n == "bones:bones" and nssm:affectbones(self) ) then
 		minetest.env:set_node(pos1, {name=p_block})
 	end
 end
@@ -313,7 +314,7 @@ function webber_ability(		--puts randomly around the block defined as w_block
 	w_block, 	--definition of the block to use
 	radius		--max distance the block can be put
 	)
-	if math.random(1,100) < nssm:virulence(self) then return end
+	if math.random(1,nssm:virulence(self)) ~= 1 then return end
 
 	local pos = self.object:getpos()
 	if (math.random(1,55)==1) then
@@ -336,6 +337,7 @@ function midas_ability(		--ability to transform every blocks it touches in the m
 	mult, 		--multiplier of the dimensions of the area around that need the transformation
 	height 		--height of the mob
 	)
+	if math.random(1,nssm:virulence(self)) ~= 1 then return end
 
 	local v = self.object:getvelocity()
 	local pos = self.object:getpos()
@@ -374,7 +376,7 @@ function midas_ability(		--ability to transform every blocks it touches in the m
 				local p = {x=pos.x+dx, y=pos.y+dy, z=pos.z+dz}
 				local n = minetest.env:get_node(p).name
 
-				if minetest.get_item_group(n, "unbreakable") == 1 or minetest.is_protected(p, "") or n=="air" or not nssm:affectbones(self) then
+				if minetest.get_item_group(n, "unbreakable") == 1 or minetest.is_protected(p, "") or n=="air" or (n == "bones:bones" and not nssm:affectbones(self)) then
 				else
 					minetest.env:set_node(p, {name=m_block})
 				end