diff --git a/README.md b/README.md
index 47329fc..c5fb9c8 100644
--- a/README.md
+++ b/README.md
@@ -17,6 +17,7 @@ get all animals to the other side.
 ## Constraints
 
 * Wolves eat foxes.  
+* Wolves eat chickens. 
 * Foxes eat chickens.  
 * Chickens eat worms.