diff --git a/characters/pests/Slug.gd b/characters/pests/Slug.gd
index 29eb8b5..65c39cb 100644
--- a/characters/pests/Slug.gd
+++ b/characters/pests/Slug.gd
@@ -8,13 +8,35 @@ onready var _agent: NavigationAgent2D = $NavigationAgent2D
 
 var target: Node2D = null
 
+var eaten_olives: int = 0
+var hp: float = 0
+
+
 # Called when the node enters the scene tree for the first time.
 func _ready():
 	call_deferred("_find_target")
 
 func _find_target() -> void:
-	target = find_parent("YSort").get_node("Player")
-	_agent.set_target_location(target.global_position)
+	if eaten_olives >= 5:
+		# go in for the kill
+		target = find_parent("YSort").get_node("Player")
+	else:
+		var trees := get_tree().get_nodes_in_group("olive_trees")
+		var best_tree = null
+		var best_tree_juiciness = -1
+		for tree in trees:
+			var tree_distsq = self.global_position.distance_squared_to(tree.global_position)
+			var tree_food = tree.calculate_food(sqrt(tree_distsq) / SPEED)
+			var tree_juiciness = tree_food / tree_distsq
+			
+			if tree_juiciness > best_tree_juiciness:
+				best_tree = tree
+				best_tree_juiciness = tree_juiciness
+		
+		target = best_tree
+	
+	if target != null:
+		_agent.set_target_location(target.global_position)
 	
 func _at_target() -> void:
 	print("at target")
@@ -36,9 +58,37 @@ func _physics_process(delta: float) -> void:
 	if _velocity.length_squared() > 16:
 		if $AnimatedSprite.animation != "crawl":
 			$AnimatedSprite.play("crawl")
+		if not $SlimyWalkSfx.playing:
+			$SlimyWalkSfx.play()
 	else:
 		if $AnimatedSprite.animation != "still":
 			$AnimatedSprite.play("still")
+		$SlimyWalkSfx.playing = false
 	
 	#print(_velocity)
 	var _vel := move_and_slide(_velocity)
+
+func _on_hp_updated() -> void:
+	if hp == eaten_olives:
+		self.modulate.a = 1.0
+	else:
+		self.modulate.a = clamp(sqrt(hp / eaten_olives), 0.0, 1.0)
+
+func _on_eaten_olives_updated() -> void:
+	self.scale = Vector2(1, 1) * (1.0 + eaten_olives * 0.1)
+	var non_red := 1.0 - (0.1 * eaten_olives)
+	self.modulate.g = non_red
+	self.modulate.b = non_red
+
+func interact(_player: Node2D) -> bool:
+	self.hp -= 1
+	if self.hp < 0:
+		# the slug is dead!
+		$SlimyWalkSfx.stop()
+		target = null
+		# TODO sfx
+		self.queue_free()
+	else:
+		self._on_hp_updated()
+	
+	return true
diff --git a/characters/pests/Slug.tscn b/characters/pests/Slug.tscn
index a545fbc..ef4ab97 100644
--- a/characters/pests/Slug.tscn
+++ b/characters/pests/Slug.tscn
@@ -1,4 +1,4 @@
-[gd_scene load_steps=10 format=2]
+[gd_scene load_steps=11 format=2]
 
 [ext_resource path="res://characters/pests/slug_frame0005.png" type="Texture" id=1]
 [ext_resource path="res://characters/pests/slug_frame0004.png" type="Texture" id=2]
@@ -7,13 +7,14 @@
 [ext_resource path="res://characters/pests/slug_frame0002.png" type="Texture" id=5]
 [ext_resource path="res://characters/pests/slug_frame0001.png" type="Texture" id=6]
 [ext_resource path="res://characters/pests/Slug.gd" type="Script" id=7]
+[ext_resource path="res://sfx/slimy_walk.wav" type="AudioStream" id=8]
 
 [sub_resource type="SpriteFrames" id=1]
 animations = [ {
-"frames": [ ExtResource( 4 ), ExtResource( 6 ), ExtResource( 5 ), ExtResource( 3 ), ExtResource( 2 ), ExtResource( 1 ) ],
+"frames": [ ExtResource( 4 ), ExtResource( 6 ), ExtResource( 5 ), ExtResource( 3 ), ExtResource( 2 ), ExtResource( 1 ), ExtResource( 3 ), ExtResource( 5 ), ExtResource( 6 ), ExtResource( 4 ) ],
 "loop": true,
 "name": "crawl",
-"speed": 5.0
+"speed": 7.0
 }, {
 "frames": [ ExtResource( 4 ) ],
 "loop": true,
@@ -26,7 +27,7 @@ radius = 6.0
 height = 40.0
 
 [node name="Slug" type="KinematicBody2D"]
-collision_layer = 0
+collision_layer = 2
 collision_mask = 0
 script = ExtResource( 7 )
 
@@ -45,3 +46,6 @@ shape = SubResource( 2 )
 path_desired_distance = 8.0
 target_desired_distance = 12.0
 path_max_distance = 64.0
+
+[node name="SlimyWalkSfx" type="AudioStreamPlayer2D" parent="."]
+stream = ExtResource( 8 )
diff --git a/scenery/facilities/OliveTree.gd b/scenery/facilities/OliveTree.gd
index 99696da..3800816 100644
--- a/scenery/facilities/OliveTree.gd
+++ b/scenery/facilities/OliveTree.gd
@@ -1,10 +1,7 @@
 extends StaticBody2D
 
 
-# Declare member variables here. Examples:
-# var a = 2
-# var b = "text"
-
+var has_been_munched: bool = false
 
 # Called when the node enters the scene tree for the first time.
 func _ready():
@@ -23,3 +20,17 @@ func interact(_player):
 				$FallSfx.pitch_scale = rand_range(0.9, 1.5)
 				$FallSfx.play()
 				break
+
+# Calculate some measure of food that makes this tree attractive to pests.
+# Calculate it in a given time.
+func calculate_food(in_time: float) -> float:
+	var food = 0
+	if not has_been_munched:
+		# munching a tree is worth 2 foods
+		food += 2
+	
+	for child in self.get_children():
+		if child.has_method("drop_olive"):
+			food += child.calculate_food_on_bud(in_time)
+	
+	return food
diff --git a/scenery/facilities/OliveTree.tscn b/scenery/facilities/OliveTree.tscn
index 5aa812b..e263100 100644
--- a/scenery/facilities/OliveTree.tscn
+++ b/scenery/facilities/OliveTree.tscn
@@ -9,7 +9,7 @@
 radius = 28.0
 height = 34.0
 
-[node name="OliveTree" type="StaticBody2D" groups=["interactable"]]
+[node name="OliveTree" type="StaticBody2D" groups=["interactable", "olive_trees"]]
 collision_layer = 3
 script = ExtResource( 3 )
 
diff --git a/scenery/facilities/OliveTreeBud.gd b/scenery/facilities/OliveTreeBud.gd
index f288903..5bafa16 100644
--- a/scenery/facilities/OliveTreeBud.gd
+++ b/scenery/facilities/OliveTreeBud.gd
@@ -58,3 +58,6 @@ func drop_olive():
 	self.reset()
 	
 	return true
+
+func calculate_food_on_bud(in_time: float) -> float:
+	return clamp(progress + in_time * grow_rate, 0.0, 1.0)
diff --git a/sfx/slimy_walk.wav b/sfx/slimy_walk.wav
new file mode 100644
index 0000000..0239412
--- /dev/null
+++ b/sfx/slimy_walk.wav
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:e21975f8f09b6312f901d1a7dd589f6f54b27e37d9f14a0f3045c2db31bc7dd9
+size 212770
diff --git a/sfx/slimy_walk.wav.import b/sfx/slimy_walk.wav.import
new file mode 100644
index 0000000..a7a4bb3
--- /dev/null
+++ b/sfx/slimy_walk.wav.import
@@ -0,0 +1,23 @@
+[remap]
+
+importer="wav"
+type="AudioStreamSample"
+path="res://.import/slimy_walk.wav-79debdca905c40e38b83ce06cb03b684.sample"
+
+[deps]
+
+source_file="res://sfx/slimy_walk.wav"
+dest_files=[ "res://.import/slimy_walk.wav-79debdca905c40e38b83ce06cb03b684.sample" ]
+
+[params]
+
+force/8_bit=false
+force/mono=false
+force/max_rate=false
+force/max_rate_hz=44100
+edit/trim=false
+edit/normalize=false
+edit/loop_mode=0
+edit/loop_begin=0
+edit/loop_end=-1
+compress/mode=0