Prevents borers from getting through head coverage.

code/modules/mob/living/carbon/human/human_defense.dm

@@ -134,6 +134,16 @@ emp_act
 				protection += C.armor[type]
 	return protection
 
+/mob/living/carbon/human/proc/check_head_coverage()
+
+	var/list/body_parts = list(head, wear_mask, wear_suit, w_uniform)
+	for(var/bp in body_parts)
+		if(!bp)	continue
+		if(bp && istype(bp ,/obj/item/clothing))
+			var/obj/item/clothing/C = bp
+			if(C.body_parts_covered & HEAD)
+				return 1
+	return 0
 
 /mob/living/carbon/human/proc/check_shields(var/damage = 0, var/attack_text = "the attack")
 	if(l_hand && istype(l_hand, /obj/item/weapon))//Current base is the prob(50-d/3)

code/modules/mob/living/simple_animal/borer.dm

@@ -368,6 +368,12 @@ mob/living/simple_animal/borer/proc/detatch()
 		src << "You cannot infest someone who is already infested!"
 		return
 
+	if(istype(M,/mob/living/carbon/human))
+		var/mob/living/carbon/human/H = M
+		if(H.check_head_coverage())
+			src << "You cannot get through that host's protective gear."
+			return
+
 	M << "Something slimy begins probing at the opening of your ear canal..."
 	src << "You slither up [M] and begin probing at their ear canal..."