diff --git a/packages/entity/traits/listed.trait.js b/packages/entity/traits/listed.trait.js
index 429dbfe..395eceb 100644
--- a/packages/entity/traits/listed.trait.js
+++ b/packages/entity/traits/listed.trait.js
@@ -10,15 +10,13 @@ export class Listed extends Trait {
 
   constructor(entity, params, state) {
     super(entity, params, state);
-    this.entity.list = undefined;
+    this.entity.list = null;
     this.quadTreeAabb = [];
     this.quadTreeNodes = [];
   }
 
   destroy() {
-    this.removeQuadTreeNodes();
-    delete this.entity.list;
-    this.entity.emit('removedFromList');
+    this.entity.removeFromList();
   }
 
   addQuadTreeNodes() {
@@ -96,9 +94,13 @@ export class Listed extends Trait {
     return {
 
       removeFromList: () => {
+        const list = this.entity.list;
+        if (!list) {
+          return;
+        }
         this.removeQuadTreeNodes();
-        this.entity.list = undefined;
-        this.entity.emit('removedFromList');
+        this.entity.list = null;
+        this.entity.emit('removedFromList', list);
       },
 
       setIntoList: (list) => {
diff --git a/packages/topdown/layer.js b/packages/topdown/layer.js
index a690d0d..65fc45a 100644
--- a/packages/topdown/layer.js
+++ b/packages/topdown/layer.js
@@ -116,11 +116,12 @@ export class Layer extends decorate(class {}) {
   }
 
   onEntityAddedToLayer(entity) {
-    entity.layer = this;
+    entity.setIntoLayer(this);
     this.emit('entityAdded', entity)
   }
 
   onEntityRemovedFromLayer(entity) {
+    entity.removeFromLayer();
     this.emit('entityRemoved', entity);
   }
 
diff --git a/packages/topdown/traits/layered.trait.js b/packages/topdown/traits/layered.trait.js
index 6209b27..55446a8 100644
--- a/packages/topdown/traits/layered.trait.js
+++ b/packages/topdown/traits/layered.trait.js
@@ -8,21 +8,31 @@ export class Layered extends Trait {
 
   constructor(entity, params, state) {
     super(entity, params, state);
-    this._layer = undefined;
+    this.entity.layer = null;
   }
 
   destroy() {
-    delete this._layer;
-    this.entity.emit('removedFromLayer');
+    this.entity.removeFromLayer();
   }
 
-  get layer() {
-    return this._layer;
-  }
+  methods() {
+    return {
 
-  set layer(layer) {
-    this._layer = layer;
-    this.entity.emit('addedToLayer');
+      removeFromLayer: () => {
+        const layer = this.entity.layer;
+        if (!layer) {
+          return;
+        }
+        this.entity.layer = null;
+        this.entity.emit('removedFromLayer', layer);
+      },
+
+      setIntoLayer: (layer) => {
+        this.entity.layer = layer;
+        this.entity.emit('addedToLayer');
+      },
+
+    };
   }
 
 }
diff --git a/packages/topdown/traits/roomed.trait.js b/packages/topdown/traits/roomed.trait.js
index 953c657..3c31e47 100644
--- a/packages/topdown/traits/roomed.trait.js
+++ b/packages/topdown/traits/roomed.trait.js
@@ -7,9 +7,7 @@ export class Roomed extends Trait {
   }
 
   destroy() {
-    const room = this.entity.room;
-    this.entity.room = null;
-    this.entity.emit('removedFromRoom', room);
+    this.entity.removeFromRoom();
   }
 
   methods() {
@@ -17,7 +15,10 @@ export class Roomed extends Trait {
 
       removeFromRoom: () => {
         const room = this.entity.room;
-        this.entity.room = undefined;
+        if (!room) {
+          return;
+        }
+        this.entity.room = null;
         this.entity.emit('removedFromRoom', room);
       },