diff --git a/site/pages/pet.md b/site/pages/pet.md
index e3bcec2..e726033 100644
--- a/site/pages/pet.md
+++ b/site/pages/pet.md
@@ -80,6 +80,7 @@ embed:
 		<summary>06/25/2024</summary>
 		<ul>
 			<li>pets now are simulated even if the page is unloaded</li>
+			<li>when pets are unhappy &lt;redacted&gt;<!-- their hidden behavior stat drops --></li>
 		</p>
 	</details>
 </details>
diff --git a/site/root/js/pet.js b/site/root/js/pet.js
index 82badae..eb0ad07 100644
--- a/site/root/js/pet.js
+++ b/site/root/js/pet.js
@@ -27,6 +27,8 @@
   const HAPPINESS_EMPTY_STOMACH_MODIFIER = -10 / UPDATES_PER_HOUR;
   /** how quickly a pet's happiness will be reduced by when their space is messy, per piece of mess */
   const HAPPINESS_MESS_MODIFIER = -5 / UPDATES_PER_HOUR;
+  /** how quickly a pet's behavior drops when unhappy */
+  const BEHAVIOR_UNHAPPY_MODIFIER = -5 / UPDATES_PER_HOUR;
 
   /** the amount of happiness gained when the pet is fed (excluding when the pet doesn't yet need food) */
   const FEED_HAPPINESS = 5;
@@ -192,6 +194,10 @@
           }
         }
 
+        if (this.happiness <= 0) {
+          this.behavior -= BEHAVIOR_UNHAPPY_MODIFIER;
+        }
+
         if (this.pottyTimer < 0) {
           this.goPotty();
         }