Ported ventcrawling from vg.

code/modules/mob/living/carbon/metroid/metroid.dm

@@ -381,8 +381,3 @@
 			powerlevel = 10
 			adjustToxLoss(-10)
 	nutrition = max(nutrition, get_max_nutrition())
-
-/mob/living/carbon/slime/cannot_use_vents()
-	if(Victim)
-		return "You cannot ventcrawl while feeding."
-	..()

code/modules/mob/living/living.dm

@@ -636,126 +636,10 @@ default behaviour is:
 	resting = !resting
 	src << "<span class='notice'>You are now [resting ? "resting" : "getting up"]</span>"
 
-/mob/living/proc/is_allowed_vent_crawl_item(var/obj/item/carried_item)
-	return (get_inventory_slot(carried_item) == 0)
-
-/mob/living/simple_animal/spiderbot/is_allowed_vent_crawl_item(var/obj/item/carried_item)
-	if(carried_item == held_item)
-		return 0
-	return ..()
-
-//called when the mob receives a bright flash
-/mob/living/flash_eyes(intensity = FLASH_PROTECTION_MODERATE, override_blindness_check = FALSE, affect_silicon = FALSE, visual = FALSE, type = /obj/screen/fullscreen/flash)
-	if(override_blindness_check || !(disabilities & BLIND))
-		overlay_fullscreen("flash", type)
-		spawn(25)
-			if(src)
-				clear_fullscreen("flash", 25)
-		return 1
-
-/mob/living/proc/handle_ventcrawl(var/obj/machinery/atmospherics/unary/vent_pump/vent_found = null, var/ignore_items = 0) // -- TLE -- Merged by Carn
-	if(stat)
-		src << "You must be conscious to do this!"
-		return
-	if(lying)
-		src << "You can't vent crawl while you're stunned!"
-		return
-	var/special_fail_msg = cannot_use_vents()
-	if(special_fail_msg)
-		src << "<span class='warning'>[special_fail_msg]</span>"
-		return
-
-	if(vent_found) // one was passed in, probably from vent/AltClick()
-		if(vent_found.welded)
-			src << "That vent is welded shut."
-			return
-		if(!vent_found.Adjacent(src))
-			return // don't even acknowledge that
-	else
-		for(var/obj/machinery/atmospherics/unary/vent_pump/v in range(1,src))
-			if(!v.welded)
-				if(v.Adjacent(src))
-					vent_found = v
-	if(!vent_found)
-		src << "You'll need a non-welded vent to crawl into!"
-		return
-
-	if(!vent_found.network || !vent_found.network.normal_members.len)
-		src << "This vent is not connected to anything."
-		return
-
-	var/list/vents = list()
-	for(var/obj/machinery/atmospherics/unary/vent_pump/temp_vent in vent_found.network.normal_members)
-		if(temp_vent.welded)
-			continue
-		if(temp_vent in loc)
-			continue
-		var/turf/T = get_turf(temp_vent)
-
-		if(!T || T.z != loc.z)
-			continue
-
-		var/i = 1
-		var/index = "[T.loc.name]\[[i]\]"
-		while(index in vents)
-			i++
-			index = "[T.loc.name]\[[i]\]"
-		vents[index] = temp_vent
-	if(!vents.len)
-		src << "\red There are no available vents to travel to, they could be welded."
-		return
-
-	var/obj/selection = input("Select a destination.", "Duct System") as null|anything in sortAssoc(vents)
-	if(!selection)	return
-
-	if(!vent_found.Adjacent(src))
-		src << "Never mind, you left."
-		return
-
-	if(!ignore_items)
-		var/list/badItems = list()
-		for(var/obj/item/carried_item in contents)//If the monkey got on objects.
-			if(!is_allowed_vent_crawl_item(carried_item))
-				badItems += carried_item.name
-		if(badItems.len)
-			src << "<span class='warning'>Your [english_list(badItems)] prevent[badItems.len == 1 ? "s" : ""] you from ventcrawling.</span>"
-			return
-
-	if(isslime(src))
-		var/mob/living/carbon/slime/S = src
-		if(S.Victim)
-			src << "\red You'll have to let [S.Victim] go or finish eating \him first."
-			return
-
-	var/obj/machinery/atmospherics/unary/vent_pump/target_vent = vents[selection]
-	if(!target_vent)
-		return
-
-	for(var/mob/O in viewers(src, null))
-		O.show_message(text("<B>[src] scrambles into the ventillation ducts!</B>"), 1)
-	loc = target_vent
-
-	var/travel_time = round(get_dist(loc, target_vent.loc) / 2)
-
-	spawn(travel_time)
-
-		if(!target_vent)	return
-		for(var/mob/O in hearers(target_vent,null))
-			O.show_message("You hear something squeezing through the ventilation ducts.",2)
-
-		sleep(travel_time)
-
-		if(!target_vent)	return
-		if(target_vent.welded)			//the vent can be welded while alien scrolled through the list or travelled.
-			target_vent = vent_found 	//travel back. No additional time required.
-			src << "\red The vent you were heading to appears to be welded."
-		loc = target_vent.loc
-		var/area/new_area = get_area(loc)
-		if(new_area)
-			new_area.Entered(src)
-
 /mob/living/proc/cannot_use_vents()
-	return "You can't fit into that vent."
+	if(mob_size > MOB_SMALL)
+		return "You can't fit into that vent."
+	return null
 
 /mob/living/proc/has_brain()
 	return 1

code/modules/mob/living/living_powers.dm

@@ -1,13 +1,3 @@
-/mob/living/proc/ventcrawl()
-	set name = "Crawl through Vent"
-	set desc = "Enter an air vent and crawl through the pipe system."
-	set category = "Abilities"
-
-	if(stat == DEAD || paralysis || weakened || stunned || restrained())
-		return
-
-	handle_ventcrawl()
-
 /mob/living/proc/hide()
 	set name = "Hide"
 	set desc = "Allows to hide beneath tables or certain items. Toggled on or off."