The ToString method is a method that belongs to the object class. We've seen it in the past multiple times when Intellisense has shown it as an optional member to use.
This is because all classes inherit from the object class where this method lives. If we F12 on ToString we can see the object class in its entirety.
Note that the ToString method is virtual. This means that we can override it if we want to give it a different behavior. Let's see what the default behavior is first.
When we call ToString on the Food item, it returns a string of the Value of that object ("ZooScenario.Food"). Snooze, right? It doesn't tell us much of anything. So let's override that method to make it do something better. To do this, we need to override the ToString method in the Food class and give it it's behavior.
Let's look at the same ToString call on the Food object.
Now we have a lot more information brought back to us than just "ZooScenario.Food"