Solution

src/herbivoresAndCarnivores.js

@@ -1,15 +1,50 @@
 'use strict';
 
 class Animal {
-  // write your code here
+  static alive = [];
+
+  constructor(name, health = 100) {
+    this.name = name;
+    this.health = health;
+    Animal.alive.push(this);
+  }
+
+  die() {
+    const index = Animal.alive.indexOf(this);
+
+    if (index > -1) {
+      Animal.alive.splice(index, 1);
+    }
+  }
+
+  checkDeath() {
+    if (this.health <= 0) {
+      this.die();
+    }
+  }
 }
 
 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
+  constructor(name, health = 100) {
+    super(name, health);
+  }
+  bite(herbivore) {
+    if (herbivore instanceof Herbivore && !herbivore.hidden) {
+      herbivore.health -= 50;
+      herbivore.checkDeath();
+    }
+  }
 }
 
 module.exports = {