为什么不能使用私有抽象方法？

假设我有我的经典作品：

Let's say I have my classic:

public abstract class Mammal {
    private int numLegs;
    private String voice;
    private Coat coat;

    public abstract void eat();

    public abstract void speak();
    public abstract void sleep();  


    private abstract void ingestFood(Food f);  //The abstract method ingestFood in type Mammal can only set a visibility modifier, one of public or protected
}

通过以下具体实现：

public class Dog extends Mammal {
     private int numLegs = 4;
     private String voice = "Woof!";
     private Coat coat = new Coat(COATTYPE.FUR, COATCOLOR.BROWN);

     @Override
     public void eat()
     { 
          Rabbit r = chaseRabbits(); 
          if (r != null) ingest(r); 
          else {
                   Garbage g = raidBin(); 
                   if (g!= null) ingest(g); 
               }


     }

     @Override
     private void ingest(Food f)
     {
         gobbleItAllUpInFiveSeconds(f); 
         stillFeelHungry(); 
     }
}

public class Human extends Mammal {
     private int numLegs = 2;
     private String voice = "Howdy!!";
     private Coat coat = new Coat(COATTYPE.SKIN, COATCOLOR.PINK);

     @Override
     public void eat()
     { 
          Food f = gotoSuperMarket();
          ingest(f); 


     }

     @Override
     private void ingest(Food f)
     {
         burp();  
     }
}

现在，我想在哺乳动物类，哺乳动物的所有实例均可调用，例如

Now, I want a method in the Mammal class that is callable by all instances of the mammal, e.g.

public String describe() {
     return "This mammal has " + this.numLegs + "legs, a " + this.coat.getColor() + " " this.coat.getCoatType() + " and says " + this.voice;
}

我的问题是，通过制作 Mammal 类不是抽象的，是否有可能单独创建哺乳动物？例如，

My question is that, by making the Mammal class not abstract, is it possible to create a mammal by itself? E.g.

 Mammal me = new Mammal();

您不应该这样做。

但是，我确实希望有一些由父类实现的公共方法，所有子类都调用这些方法，但是每个子类都调用自己的私有方法。

However, I do want to have some public methods that are implemented by the parent class that all subclasses call, but that each call their own private method.