diff --git a/code/game/gamemodes/miniantags/abduction/gland.dm b/code/game/gamemodes/miniantags/abduction/gland.dm
index 5495f914de1..0cb5317bb8a 100644
--- a/code/game/gamemodes/miniantags/abduction/gland.dm
+++ b/code/game/gamemodes/miniantags/abduction/gland.dm
@@ -190,7 +190,7 @@
 
 /obj/item/organ/internal/heart/gland/ventcrawling/activate()
 	to_chat(owner, "<span class='notice'>You feel very stretchy.</span>")
-	owner.ventcrawler = 2
+	owner.ventcrawler = VENTCRAWLER_ALWAYS
 
 
 /obj/item/organ/internal/heart/gland/viral
diff --git a/code/game/gamemodes/miniantags/morph/morph.dm b/code/game/gamemodes/miniantags/morph/morph.dm
index edc1b5704d9..be867dcdab5 100644
--- a/code/game/gamemodes/miniantags/morph/morph.dm
+++ b/code/game/gamemodes/miniantags/morph/morph.dm
@@ -17,7 +17,7 @@
 	status_flags = CANPUSH
 	pass_flags = PASSTABLE
 	move_resist = MOVE_FORCE_STRONG // Fat being
-	ventcrawler = 2
+	ventcrawler = VENTCRAWLER_ALWAYS
 
 	atmos_requirements = list("min_oxy" = 0, "max_oxy" = 0, "min_tox" = 0, "max_tox" = 0, "min_co2" = 0, "max_co2" = 0, "min_n2" = 0, "max_n2" = 0)
 
diff --git a/code/game/gamemodes/miniantags/morph/spells/reproduce.dm b/code/game/gamemodes/miniantags/morph/spells/reproduce.dm
index 7f3ec3b00c5..814c16cc06a 100644
--- a/code/game/gamemodes/miniantags/morph/spells/reproduce.dm
+++ b/code/game/gamemodes/miniantags/morph/spells/reproduce.dm
@@ -20,7 +20,7 @@
 
 /obj/effect/proc_holder/spell/morph_spell/reproduce/cast(list/targets, mob/living/simple_animal/hostile/morph/user)
 	to_chat(user, "<span class='sinister'>You prepare to split in two, making you unable to vent crawl!</span>")
-	user.ventcrawler = FALSE // Temporarily disable it
+	user.ventcrawler = VENTCRAWLER_NONE // Temporarily disable it
 	var/list/candidates = SSghost_spawns.poll_candidates("Do you want to play as a morph?", ROLE_MORPH, TRUE, poll_time = 10 SECONDS, source = /mob/living/simple_animal/hostile/morph)
 	if(!length(candidates))
 		to_chat(user, "<span class='warning'>Your body refuses to split at the moment. Try again later.</span>")
diff --git a/code/modules/clothing/under/jobs/engineering_jumpsuits.dm b/code/modules/clothing/under/jobs/engineering_jumpsuits.dm
index 0a48a71555c..d3333052aed 100644
--- a/code/modules/clothing/under/jobs/engineering_jumpsuits.dm
+++ b/code/modules/clothing/under/jobs/engineering_jumpsuits.dm
@@ -39,12 +39,12 @@
 
 /obj/item/clothing/under/rank/engineering/atmospheric_technician/contortionist/equipped(mob/living/carbon/human/user, slot)
 	if(!user.ventcrawler)
-		user.ventcrawler = 2
+		user.ventcrawler = VENTCRAWLER_ALWAYS
 	..()
 
 /obj/item/clothing/under/rank/engineering/atmospheric_technician/contortionist/dropped(mob/living/carbon/human/user)
 	if(!user.get_int_organ(/obj/item/organ/internal/heart/gland/ventcrawling))
-		user.ventcrawler = 0
+		user.ventcrawler = VENTCRAWLER_NONE
 	..()
 
 /obj/item/clothing/under/rank/engineering/atmospheric_technician/contortionist/proc/check_clothing(mob/user as mob)
diff --git a/code/modules/mining/lavaland/loot/colossus_loot.dm b/code/modules/mining/lavaland/loot/colossus_loot.dm
index 9fdd6258241..102a38f71ff 100644
--- a/code/modules/mining/lavaland/loot/colossus_loot.dm
+++ b/code/modules/mining/lavaland/loot/colossus_loot.dm
@@ -263,7 +263,7 @@
 	flying = TRUE
 	obj_damage = 0
 	pass_flags = PASSTABLE | PASSGRILLE | PASSMOB
-	ventcrawler = 2
+	ventcrawler = VENTCRAWLER_ALWAYS
 	mob_size = MOB_SIZE_TINY
 	gold_core_spawnable = HOSTILE_SPAWN
 	speak_emote = list("warps")
diff --git a/code/modules/mob/living/carbon/alien/alien_base.dm b/code/modules/mob/living/carbon/alien/alien_base.dm
index 5ff5e60a581..cc8f61a59c3 100644
--- a/code/modules/mob/living/carbon/alien/alien_base.dm
+++ b/code/modules/mob/living/carbon/alien/alien_base.dm
@@ -20,7 +20,7 @@
 	var/loudspeaker = FALSE
 	var/heat_protection = 0.5
 	var/leaping = FALSE
-	ventcrawler = 2
+	ventcrawler = VENTCRAWLER_ALWAYS
 	var/death_message = "lets out a waning guttural screech, green blood bubbling from its maw..."
 	var/death_sound = 'sound/voice/hiss6.ogg'
 
diff --git a/code/modules/mob/living/carbon/alien/humanoid/empress.dm b/code/modules/mob/living/carbon/alien/humanoid/empress.dm
index 4cebd349dd8..2ab7d866323 100644
--- a/code/modules/mob/living/carbon/alien/humanoid/empress.dm
+++ b/code/modules/mob/living/carbon/alien/humanoid/empress.dm
@@ -9,7 +9,7 @@
 	mob_size = MOB_SIZE_LARGE
 	bubble_icon = "alienroyal"
 	large = 1
-	ventcrawler = 0
+	ventcrawler = VENTCRAWLER_NONE
 	move_resist = MOVE_FORCE_STRONG //Yes, big benos is huge and heavy
 	alien_disarm_damage = 60 //Empress do higher disarm stamina damage than normal aliens
 	alien_slash_damage = 30 //Empress do higher slashing damage to people
diff --git a/code/modules/mob/living/carbon/alien/humanoid/queen.dm b/code/modules/mob/living/carbon/alien/humanoid/queen.dm
index 441717a45ca..2564f8ec7b8 100644
--- a/code/modules/mob/living/carbon/alien/humanoid/queen.dm
+++ b/code/modules/mob/living/carbon/alien/humanoid/queen.dm
@@ -8,7 +8,7 @@
 	loudspeaker = TRUE
 	heal_rate = 5
 	large = 1
-	ventcrawler = 0
+	ventcrawler = VENTCRAWLER_NONE
 	pressure_resistance = 200 //Because big, stompy xenos should not be blown around like paper.
 	move_resist = MOVE_FORCE_STRONG //Yes, queenos is huge and heavy
 	alien_disarm_damage = 60 //Queens do higher disarm stamina damage than normal aliens
diff --git a/code/modules/mob/living/living_defines.dm b/code/modules/mob/living/living_defines.dm
index 4abf312b4f1..ced34a42995 100644
--- a/code/modules/mob/living/living_defines.dm
+++ b/code/modules/mob/living/living_defines.dm
@@ -42,7 +42,7 @@
 	var/mob_biotypes = MOB_ORGANIC
 	var/metabolism_efficiency = 1 //more or less efficiency to metabolize helpful/harmful reagents and regulate body temperature..
 
-	var/ventcrawler = 0 //0 No vent crawling, 1 vent crawling in the nude, 2 vent crawling always
+	var/ventcrawler = VENTCRAWLER_NONE
 	var/list/icon/pipes_shown = list()
 	var/last_played_vent
 
diff --git a/code/modules/mob/living/simple_animal/friendly/crab.dm b/code/modules/mob/living/simple_animal/friendly/crab.dm
index 69f82b4df54..10724db9ad8 100644
--- a/code/modules/mob/living/simple_animal/friendly/crab.dm
+++ b/code/modules/mob/living/simple_animal/friendly/crab.dm
@@ -16,7 +16,7 @@
 	response_harm   = "stomps"
 	stop_automated_movement = TRUE
 	friendly = "pinches"
-	ventcrawler = 2
+	ventcrawler = VENTCRAWLER_ALWAYS
 	can_hide = TRUE
 	can_collar = TRUE
 	gold_core_spawnable = FRIENDLY_SPAWN
diff --git a/code/modules/mob/living/simple_animal/friendly/diona_nymph.dm b/code/modules/mob/living/simple_animal/friendly/diona_nymph.dm
index 2e5b09867f2..9cf8dba0953 100644
--- a/code/modules/mob/living/simple_animal/friendly/diona_nymph.dm
+++ b/code/modules/mob/living/simple_animal/friendly/diona_nymph.dm
@@ -16,7 +16,7 @@
 	pass_flags = PASSTABLE | PASSMOB
 	mob_biotypes = MOB_ORGANIC | MOB_PLANT
 	mob_size = MOB_SIZE_SMALL
-	ventcrawler = 2
+	ventcrawler = VENTCRAWLER_ALWAYS
 	atmos_requirements = list("min_oxy" = 0, "max_oxy" = 0, "min_tox" = 0, "max_tox" = 0, "min_co2" = 0, "max_co2" = 0, "min_n2" = 0, "max_n2" = 0)
 	minbodytemp = 0
 
diff --git a/code/modules/mob/living/simple_animal/friendly/farm_animals.dm b/code/modules/mob/living/simple_animal/friendly/farm_animals.dm
index f0410b6ad89..c92cb90d460 100644
--- a/code/modules/mob/living/simple_animal/friendly/farm_animals.dm
+++ b/code/modules/mob/living/simple_animal/friendly/farm_animals.dm
@@ -209,7 +209,7 @@
 	attacktext = "kicks"
 	health = 3
 	maxHealth = 3
-	ventcrawler = 2
+	ventcrawler = VENTCRAWLER_ALWAYS
 	var/amount_grown = 0
 	pass_flags = PASSTABLE | PASSGRILLE | PASSMOB
 	mob_size = MOB_SIZE_TINY
@@ -264,7 +264,7 @@ GLOBAL_VAR_INIT(chicken_count, 0)
 	attacktext = "kicks"
 	health = 15
 	maxHealth = 15
-	ventcrawler = 2
+	ventcrawler = VENTCRAWLER_ALWAYS
 	var/eggsleft = 0
 	var/eggsFertile = TRUE
 	var/body_color
diff --git a/code/modules/mob/living/simple_animal/friendly/mouse.dm b/code/modules/mob/living/simple_animal/friendly/mouse.dm
index c2ff0d003d4..3d8747084b6 100644
--- a/code/modules/mob/living/simple_animal/friendly/mouse.dm
+++ b/code/modules/mob/living/simple_animal/friendly/mouse.dm
@@ -21,7 +21,7 @@
 	response_disarm = "gently pushes aside"
 	response_harm   = "stamps on"
 	density = FALSE
-	ventcrawler = 2
+	ventcrawler = VENTCRAWLER_ALWAYS
 	pass_flags = PASSTABLE | PASSGRILLE | PASSMOB
 	mob_biotypes = MOB_ORGANIC | MOB_BEAST
 	mob_size = MOB_SIZE_TINY
diff --git a/code/modules/mob/living/simple_animal/friendly/spiderbot.dm b/code/modules/mob/living/simple_animal/friendly/spiderbot.dm
index 2323be439dd..8a1a44499ca 100644
--- a/code/modules/mob/living/simple_animal/friendly/spiderbot.dm
+++ b/code/modules/mob/living/simple_animal/friendly/spiderbot.dm
@@ -30,7 +30,7 @@
 	maxbodytemp = 500
 
 	can_hide = TRUE
-	ventcrawler = 2
+	ventcrawler = VENTCRAWLER_ALWAYS
 	loot = list(/obj/effect/decal/cleanable/blood/gibs/robot)
 	del_on_death = TRUE
 
diff --git a/code/modules/mob/living/simple_animal/hostile/deathsquid.dm b/code/modules/mob/living/simple_animal/hostile/deathsquid.dm
index 31be4fc124b..f791a681b72 100644
--- a/code/modules/mob/living/simple_animal/hostile/deathsquid.dm
+++ b/code/modules/mob/living/simple_animal/hostile/deathsquid.dm
@@ -29,7 +29,7 @@
 
 	see_in_dark = 8
 	mob_size = MOB_SIZE_LARGE
-	ventcrawler = 0
+	ventcrawler = VENTCRAWLER_NONE
 	gold_core_spawnable = NO_SPAWN
 
 
diff --git a/code/modules/mob/living/simple_animal/hostile/headslug.dm b/code/modules/mob/living/simple_animal/hostile/headslug.dm
index f5e2dfafe08..f2aa53fd8ad 100644
--- a/code/modules/mob/living/simple_animal/hostile/headslug.dm
+++ b/code/modules/mob/living/simple_animal/hostile/headslug.dm
@@ -22,7 +22,7 @@
 	speak_emote = list("squeaks")
 	pass_flags = PASSTABLE | PASSMOB
 	density = FALSE
-	ventcrawler = 2
+	ventcrawler = VENTCRAWLER_ALWAYS
 	a_intent = INTENT_HARM
 	speed = 0.3
 	can_hide = TRUE
@@ -113,7 +113,7 @@
 	if(!ishuman(owner))
 		owner.gib()
 		return
-		
+
 	owner.apply_damage(300, BRUTE, BODY_ZONE_CHEST)
 	owner.bleed(BLOOD_VOLUME_NORMAL)
 	var/obj/item/organ/external/chest = owner.get_organ(BODY_ZONE_CHEST)
diff --git a/code/modules/mob/living/simple_animal/hostile/killertomato.dm b/code/modules/mob/living/simple_animal/hostile/killertomato.dm
index 46871f3d4e4..adb59e96397 100644
--- a/code/modules/mob/living/simple_animal/hostile/killertomato.dm
+++ b/code/modules/mob/living/simple_animal/hostile/killertomato.dm
@@ -18,7 +18,7 @@
 	melee_damage_upper = 12
 	attacktext = "slams"
 	attack_sound = 'sound/weapons/punch1.ogg'
-	ventcrawler = 2
+	ventcrawler = VENTCRAWLER_ALWAYS
 	faction = list("plants", "jungle")
 
 	atmos_requirements = list("min_oxy" = 5, "max_oxy" = 0, "min_tox" = 0, "max_tox" = 0, "min_co2" = 0, "max_co2" = 0, "min_n2" = 0, "max_n2" = 0)
diff --git a/code/modules/mob/living/simple_animal/hostile/mushroom.dm b/code/modules/mob/living/simple_animal/hostile/mushroom.dm
index ded4a05c710..b30334e96de 100644
--- a/code/modules/mob/living/simple_animal/hostile/mushroom.dm
+++ b/code/modules/mob/living/simple_animal/hostile/mushroom.dm
@@ -25,7 +25,7 @@
 	stat_attack = DEAD
 	mouse_opacity = MOUSE_OPACITY_ICON
 	speed = 1
-	ventcrawler = 2
+	ventcrawler = VENTCRAWLER_ALWAYS
 	robust_searching = TRUE
 	speak_emote = list("squeaks")
 	deathmessage = "fainted"
diff --git a/code/modules/mob/living/simple_animal/hostile/terror_spiders/empress_terror.dm b/code/modules/mob/living/simple_animal/hostile/terror_spiders/empress_terror.dm
index 92378e5422c..c1a6c438090 100644
--- a/code/modules/mob/living/simple_animal/hostile/terror_spiders/empress_terror.dm
+++ b/code/modules/mob/living/simple_animal/hostile/terror_spiders/empress_terror.dm
@@ -20,7 +20,7 @@
 	health = 1000
 	melee_damage_lower = 30
 	melee_damage_upper = 60
-	ventcrawler = 1
+	ventcrawler = VENTCRAWLER_NUDE
 	idle_ventcrawl_chance = 0
 	ai_playercontrol_allowtype = 0
 	canlay = 1000
diff --git a/code/modules/mob/living/simple_animal/hostile/terror_spiders/prince.dm b/code/modules/mob/living/simple_animal/hostile/terror_spiders/prince.dm
index 3fc52c744b5..6a5776414a8 100644
--- a/code/modules/mob/living/simple_animal/hostile/terror_spiders/prince.dm
+++ b/code/modules/mob/living/simple_animal/hostile/terror_spiders/prince.dm
@@ -27,7 +27,7 @@
 	speed = 0.5
 	melee_damage_lower = 30
 	melee_damage_upper = 40
-	ventcrawler = 0
+	ventcrawler = VENTCRAWLER_NONE
 	ai_ventcrawls = FALSE
 	environment_smash = ENVIRONMENT_SMASH_RWALLS
 	idle_ventcrawl_chance = 0
diff --git a/code/modules/mob/living/simple_animal/hostile/terror_spiders/purple.dm b/code/modules/mob/living/simple_animal/hostile/terror_spiders/purple.dm
index 3e742f0f6de..4e9db5de01a 100644
--- a/code/modules/mob/living/simple_animal/hostile/terror_spiders/purple.dm
+++ b/code/modules/mob/living/simple_animal/hostile/terror_spiders/purple.dm
@@ -28,7 +28,7 @@
 	move_to_delay = 5 // at 20ticks/sec, this is 4 tile/sec movespeed, same as a human. Faster than a normal spider, so it can intercept attacks on queen.
 	speed = 0 // '0' (also the default for human mobs) converts to 2.5 total delay, or 4 tiles/sec.
 	spider_opens_doors = 2
-	ventcrawler = 0
+	ventcrawler = VENTCRAWLER_NONE
 	ai_ventcrawls = FALSE
 	environment_smash = ENVIRONMENT_SMASH_RWALLS
 	idle_ventcrawl_chance = 0 // stick to the queen!
diff --git a/code/modules/mob/living/simple_animal/hostile/terror_spiders/queen_terror.dm b/code/modules/mob/living/simple_animal/hostile/terror_spiders/queen_terror.dm
index c0ab6cf9964..0966d7ed7c1 100644
--- a/code/modules/mob/living/simple_animal/hostile/terror_spiders/queen_terror.dm
+++ b/code/modules/mob/living/simple_animal/hostile/terror_spiders/queen_terror.dm
@@ -26,7 +26,7 @@
 	regen_points_per_tick = 3
 	melee_damage_lower = 10
 	melee_damage_upper = 20
-	ventcrawler = 1
+	ventcrawler = VENTCRAWLER_NUDE
 	ai_break_lights = FALSE
 	ai_spins_webs = FALSE
 	ai_ventcrawls = FALSE
@@ -236,7 +236,7 @@
 	queensense_action.Grant(src)
 	queennest_action.Remove(src)
 	hasnested = TRUE
-	ventcrawler = 0
+	ventcrawler = VENTCRAWLER_NONE
 	ai_ventcrawls = FALSE
 	environment_smash = ENVIRONMENT_SMASH_RWALLS
 	DoQueenScreech(8, 100, 8, 100)
diff --git a/code/modules/mob/living/simple_animal/hostile/terror_spiders/terror_spiders.dm b/code/modules/mob/living/simple_animal/hostile/terror_spiders/terror_spiders.dm
index bdb3bdfa445..b637b129f24 100644
--- a/code/modules/mob/living/simple_animal/hostile/terror_spiders/terror_spiders.dm
+++ b/code/modules/mob/living/simple_animal/hostile/terror_spiders/terror_spiders.dm
@@ -54,7 +54,7 @@ GLOBAL_LIST_EMPTY(ts_infected_list)
 	// '2' converts to 4.5, or 2.2 tiles/sec.
 
 	// Ventcrawling
-	ventcrawler = 1 // allows player ventcrawling
+	ventcrawler = VENTCRAWLER_NUDE // allows player ventcrawling
 	var/ai_ventcrawls = TRUE
 	var/idle_ventcrawl_chance = 15
 	var/freq_ventcrawl_combat = 1800 // 3 minutes