add solution

src/herbivoresAndCarnivores.js

@@ -2,14 +2,40 @@
 
 class Animal {
   // write your code here
+  static alive = [];
+  constructor(name) {
+    this.name = name;
+    this.health = 100;
+    Animal.alive.push(this);
+  }
 }
 
 class Herbivore extends Animal {
   // write your code here
+  constructor(name) {
+    super(name);
+    this.hidden = false;
+  }
+
+  hide() {
+    this.hidden = true;
+  }
 }
 
 class Carnivore extends Animal {
   // write your code here
+  bite(animal) {
+    if (animal instanceof Carnivore || animal.hidden) {
+      return;
+    }
+    animal.health = animal.health - 50;
+
+    if (animal.health <= 0) {
+      Animal.alive = Animal.alive.filter((currentAnimal) => {
+        return currentAnimal !== animal;
+      });
+    }
+  }
 }
 
 module.exports = {