diff --git a/src/herbivoresAndCarnivores.js b/src/herbivoresAndCarnivores.js
index 637b47ba4..65ac6e426 100644
--- a/src/herbivoresAndCarnivores.js
+++ b/src/herbivoresAndCarnivores.js
@@ -1,15 +1,40 @@
 'use strict';
-
 class Animal {
-  // write your code here
+  static alive = [];
+
+  constructor(name, health = 100) {
+    this.name = name;
+    this.health = health;
+    this.alive = true;
+    Animal.alive.push(this);
+  }
+
+  isAlive() {
+    if (this.health <= 0) {
+      this.alive = false;
+      Animal.alive = Animal.alive.filter((element) => element.alive);
+    }
+  }
 }
 
 class Herbivore extends Animal {
-  // write your code here
+  constructor(name, health = 100, hidden = false) {
+    super(name, health);
+    this.hidden = hidden;
+  }
+
+  hide() {
+    this.hidden = true;
+  }
 }
 
 class Carnivore extends Animal {
-  // write your code here
+  bite(target) {
+    if (target instanceof Herbivore && !target.hidden) {
+      target.health -= 50;
+      target.isAlive();
+    }
+  }
 }
 
 module.exports = {