diff --git a/src/Organism/Organism.js b/src/Organism/Organism.js
index 80f8404..a92d988 100644
--- a/src/Organism/Organism.js
+++ b/src/Organism/Organism.js
@@ -274,6 +274,8 @@ class Organism {
     }
 
     update() {
+        if(this.lifetime<0) this.lifetime = 0;
+        if(this.damage<0) this.damage = 0;
         this.lifetime++;
         if (this.lifetime > this.lifespan()) {
             this.die();