diff --git a/code/__DEFINES/xeno_ai.dm b/code/__DEFINES/xeno_ai.dm
index d1f0b647cd..847f649fd5 100644
--- a/code/__DEFINES/xeno_ai.dm
+++ b/code/__DEFINES/xeno_ai.dm
@@ -23,8 +23,10 @@ PROBABILITY CALCULATIONS ARE HERE
 
 #define XENO_SLASH 80
 
-#define RETREAT_AT_PLASMA_LEVEL 0.2
-#define RETREAT_AT_HEALTH_LEVEL 0.4
+#define XENO_DOOR_BUILDING_CHANCE 25
+
+#define PLASMA_RETREAT_PERCENTAGE 10
+#define HEALTH_RETREAT_PERCENTAGE 20
 
 #define LURKING_IGNORE_SHOT_CHANCE 75
 
diff --git a/code/datums/components/xeno/ai_behavior_overrides/build_override_behavior.dm b/code/datums/components/xeno/ai_behavior_overrides/build_override_behavior.dm
new file mode 100644
index 0000000000..5430c3cd03
--- /dev/null
+++ b/code/datums/components/xeno/ai_behavior_overrides/build_override_behavior.dm
@@ -0,0 +1,104 @@
+
+/datum/component/ai_behavior_override/build
+	behavior_icon_state = "priority_move_order"
+
+	max_assigned = 1
+
+/datum/component/ai_behavior_override/build/Initialize(...)
+	. = ..()
+
+	if(istype(parent, /mob))
+		return COMPONENT_INCOMPATIBLE
+
+	var/turf/open/location = get_turf(parent)
+	if(location.is_weedable() != FULLY_WEEDABLE)
+		return COMPONENT_INCOMPATIBLE
+
+/datum/component/ai_behavior_override/build/Destroy(force, silent, ...)
+	var/turf/parent_turf = get_turf(parent)
+	if(QDELETED(parent) && parent_turf != parent)
+		parent_turf.AddComponent(/datum/component/ai_behavior_override/build)
+
+	return ..()
+
+/datum/component/ai_behavior_override/build/check_behavior_validity(mob/living/carbon/xenomorph/checked_xeno, distance)
+	. = ..()
+	if(!.)
+		return
+
+	var/turf/open/location = get_turf(parent)
+	if(!istype(location))
+		qdel(src)
+		return FALSE
+
+	if(locate(/obj/structure/mineral_door/resin) in location)
+		qdel(src)
+		return FALSE
+
+	if(distance > 10)
+		return FALSE
+
+	if(checked_xeno.current_target)
+		return FALSE
+
+	if(!locate(/datum/action/xeno_action/activable/secrete_resin) in checked_xeno.actions)
+		return FALSE
+
+	if(checked_xeno.get_plasma_percentage() < PLASMA_RETREAT_PERCENTAGE)
+		var/turf/xeno_loc = get_turf(checked_xeno)
+		if(xeno_loc.weeds && !checked_xeno.resting)
+			currently_assigned -= checked_xeno
+			checked_xeno.lay_down()
+
+		return FALSE
+
+	return TRUE
+
+/datum/component/ai_behavior_override/build/process_override_behavior(mob/living/carbon/xenomorph/processing_xeno, delta_time)
+	. = ..()
+	if(!.)
+		return
+
+	processing_xeno.resting = FALSE
+
+	var/turf/xeno_loc = get_turf(processing_xeno)
+	if(xeno_loc.density)
+		return FALSE // We shouldn't stand in a wall, let's act default
+
+	var/turf/parent_turf = get_turf(parent)
+
+	var/is_diagonal = (get_dir(processing_xeno, parent_turf) in diagonals)
+	if(is_diagonal || get_dist(processing_xeno, parent) > 1)
+		return processing_xeno.move_to_next_turf(parent_turf)
+
+	for(var/obj/structure/blocker in parent_turf.contents)
+		if(!blocker.unslashable && blocker.density || istype(blocker, /obj/structure/bed))
+			INVOKE_ASYNC(processing_xeno, TYPE_PROC_REF(/mob, do_click), blocker, "", list())
+			return TRUE
+
+	if(!parent_turf.weeds)
+		var/datum/action/xeno_action/onclick/plant_weeds/weeds_action = locate() in processing_xeno.actions
+		INVOKE_ASYNC(weeds_action, TYPE_PROC_REF(/datum/action/xeno_action/onclick/plant_weeds, use_ability_wrapper))
+		return TRUE
+
+	var/list/resin_types = processing_xeno.resin_build_order
+	processing_xeno.selected_resin = locate(/datum/resin_construction/resin_turf/wall) in resin_types
+
+	var/wall_nearby
+	var/blocked_turfs = 0
+	for(var/turf/blocked_turf in orange(1, parent_turf) - parent_turf.AdjacentTurfs())
+		if(get_dir(blocked_turf, parent_turf) in diagonals)
+			continue
+
+		if(blocked_turf.density)
+			wall_nearby = TRUE
+
+		blocked_turfs++
+
+	if(blocked_turfs)
+		if(prob(XENO_DOOR_BUILDING_CHANCE) || (wall_nearby && blocked_turfs == 2))
+			processing_xeno.selected_resin = locate(/datum/resin_construction/resin_obj/door) in resin_types
+
+	var/datum/action/xeno_action/activable/secrete_resin/build_action = locate() in processing_xeno.actions
+	INVOKE_ASYNC(build_action, TYPE_PROC_REF(/datum/action/xeno_action/activable/secrete_resin, use_ability_wrapper), parent_turf)
+	return TRUE
diff --git a/code/modules/admin/game_master/game_master.dm b/code/modules/admin/game_master/game_master.dm
index 6472563af5..c5ad7e7949 100644
--- a/code/modules/admin/game_master/game_master.dm
+++ b/code/modules/admin/game_master/game_master.dm
@@ -35,8 +35,8 @@ GLOBAL_VAR_INIT(radio_communication_clarity, 100)
 
 // Behavior stuff
 #define DEFAULT_BEHAVIOR_STRING "Attack"
-#define SELECTABLE_XENO_BEHAVIORS list("Attack", "Capture", "Hive")
-#define SELECTABLE_XENO_BEHAVIORS_ASSOC list("Attack" = /datum/component/ai_behavior_override/attack, "Capture" = /datum/component/ai_behavior_override/capture, "Hive" = /datum/component/ai_behavior_override/hive)
+#define SELECTABLE_XENO_BEHAVIORS list("Attack", "Capture", "Hive", "Build")
+#define SELECTABLE_XENO_BEHAVIORS_ASSOC list("Attack" = /datum/component/ai_behavior_override/attack, "Capture" = /datum/component/ai_behavior_override/capture, "Hive" = /datum/component/ai_behavior_override/hive, "Build" = /datum/component/ai_behavior_override/build)
 
 // Objective stuff
 #define OBJECTIVE_NUMBER_OPTIONS list("zero", "one", "two", "three", "four", "five", "six", "seven", "eight", "nine")
diff --git a/code/modules/mob/living/carbon/xenomorph/attack_alien.dm b/code/modules/mob/living/carbon/xenomorph/attack_alien.dm
index b5a8cfff51..c294d3c2a1 100644
--- a/code/modules/mob/living/carbon/xenomorph/attack_alien.dm
+++ b/code/modules/mob/living/carbon/xenomorph/attack_alien.dm
@@ -900,6 +900,7 @@
 				M.visible_message(SPAN_DANGER("[M] smashes \the [src] open!"), \
 				SPAN_DANGER("You smash \the [src] open!"), null, 5, CHAT_TYPE_XENO_COMBAT)
 		else
+			take_damage(M.melee_damage_upper)
 			M.visible_message(SPAN_DANGER("[M] smashes [src]!"), \
 			SPAN_DANGER("You smash [src]!"), null, 5, CHAT_TYPE_XENO_COMBAT)
 		return XENO_ATTACK_ACTION
diff --git a/code/modules/mob/living/carbon/xenomorph/resin_constructions.dm b/code/modules/mob/living/carbon/xenomorph/resin_constructions.dm
index 3bfb4e3554..bad467288e 100644
--- a/code/modules/mob/living/carbon/xenomorph/resin_constructions.dm
+++ b/code/modules/mob/living/carbon/xenomorph/resin_constructions.dm
@@ -20,11 +20,6 @@ GLOBAL_VAR_INIT(resin_lz_allowed, FALSE)
 	var/can_build_on_doors = TRUE // if it can be built on a tile with an open door or not
 
 /datum/resin_construction/proc/can_build_here(turf/T, mob/living/carbon/xenomorph/X)
-	var/mob/living/carbon/xenomorph/blocker = locate() in T
-	if(blocker && blocker != X && blocker.stat != DEAD)
-		to_chat(X, SPAN_WARNING("Can't do that with [blocker] in the way!"))
-		return FALSE
-
 	if(!istype(T) || T.is_weedable() < FULLY_WEEDABLE)
 		to_chat(X, SPAN_WARNING("You can't do that here."))
 		return FALSE
diff --git a/colonialmarines.dme b/colonialmarines.dme
index b1fc28f93e..2cf8f184e8 100644
--- a/colonialmarines.dme
+++ b/colonialmarines.dme
@@ -401,6 +401,7 @@
 #include "code\datums\components\xeno\shield_slash.dm"
 #include "code\datums\components\xeno\ai_behavior_overrides\attack_override_behavior.dm"
 #include "code\datums\components\xeno\ai_behavior_overrides\base_override_behavior.dm"
+#include "code\datums\components\xeno\ai_behavior_overrides\build_override_behavior.dm"
 #include "code\datums\components\xeno\ai_behavior_overrides\capture_override_behavior.dm"
 #include "code\datums\components\xeno\ai_behavior_overrides\hive_override_behavior.dm"
 #include "code\datums\construction\construction_template.dm"