Tweaks carp/dweller behavior and the spawn chances of a couple of major events (#10024)

code/modules/mob/living/simple_animal/friendly/carp.dm

@@ -21,6 +21,8 @@
 	response_disarm = "attempts to push"
 	response_harm = "injures"
 	gender = NEUTER
+	faction = "carp"
+	flying = TRUE
 
 	//Space carp aren't affected by atmos.
 	min_oxy = 0

code/modules/mob/living/simple_animal/hostile/carp.dm

@@ -74,10 +74,12 @@
 		return e
 
 /mob/living/simple_animal/hostile/carp/DestroySurroundings(var/bypass_prob = FALSE)
+	if(stance != HOSTILE_STANCE_ATTACKING)
+		return 0
 	if(prob(break_stuff_probability) || bypass_prob)
 		for(var/dir in cardinal) // North, South, East, West
 			var/obj/effect/energy_field/e = locate(/obj/effect/energy_field, get_step(src, dir))
-			if(e)
+			if(e && e.strength >= 1)
 				e.Stress(rand(1,2))
 				visible_message("<span class='danger'>\the [src] bites \the [e]!</span>")
 				src.do_attack_animation(e)

code/modules/mob/living/simple_animal/hostile/retaliate/cavern.dm

@@ -60,6 +60,12 @@
 	tracer_type = /obj/effect/projectile/tracer/stun
 	impact_type = /obj/effect/projectile/impact/stun
 
+/mob/living/simple_animal/hostile/retaliate/cavern_dweller/DestroySurroundings(var/bypass_prob = FALSE)
+	if(stance != HOSTILE_STANCE_ATTACKING)
+		return 0
+	else
+		..()
+
 /obj/item/projectile/beam/cavern/on_hit(var/atom/target, var/blocked = 0)
 	if(ishuman(target))
 		var/mob/living/carbon/human/M = target