Prevents xenos evolving in pipes

code/modules/mob/living/carbon/alien/humanoid/caste/drone.dm

@@ -30,7 +30,9 @@
 	if(node.recent_queen_death)
 		to_chat(user, "<span class='danger'>Your thoughts are still too scattered to take up the position of leadership.</span>")
 		return 0
-
+	if(user.movement_type & (VENTCRAWLING))
+		to_chat(user, "<span class='danger'>You cannot evolve in a pipe.</span>")
+		return 0
 	if(!isturf(user.loc))
 		to_chat(user, "<span class='notice'>You can't evolve here!</span>")
 		return 0

code/modules/mob/living/carbon/alien/larva/powers.dm

@@ -36,6 +36,10 @@
 		to_chat(user, "<span class='danger'>You cannot evolve when you are cuffed.</span>")
 		return
 
+	if(L.movement_type & (VENTCRAWLING))
+		to_chat(user, "<span class='danger'>You cannot evolve in a pipe.</span>")
+		return
+
 	if(L.amount_grown >= L.max_grown)	//TODO ~Carn
 		to_chat(L, "<span class='name'>You are growing into a beautiful alien! It is time to choose a caste.</span>")
 		to_chat(L, "<span class='info'>There are three to choose from:</span>")
@@ -47,6 +51,10 @@
 		if(user.incapacitated()) //something happened to us while we were choosing.
 			return
 
+		if(L.movement_type & (VENTCRAWLING))
+			to_chat(user, "<span class='danger'>You cannot evolve in a pipe.</span>")
+			return
+
 		var/mob/living/carbon/alien/humanoid/new_xeno
 		switch(alien_caste)
 			if("Hunter")