PHP: __construct() question

[potatoCode]

Hello php gurus

If a class has a method named after the class, is the function constructor?
If I have a base class as

// Inheritance test
class Animal
{

    function __construct($ref)
    {
        $this->animalName = $ref;
    }

    function eat()
    {
        printf("%s is eating<br />", $this->animalName);
    }

    protected $animalName;
    
} 

and I'd like to call the base's constructor in the derived

//
class Panda extends Animal
{
    function __construct($ref)
    {
        $this->Animal($ref); //works only if Animal($ref) is defined in the base
    }

    function eat()
    {
        printf("Big %s is eating<br />", $this->animalName);
        return $this;
    }

    function yawn()
    {
        printf("Big %s is yawning<br />", $this->animalName);
    }
} 

What is the difference between __construct() and the function with the same class name?

Thanks for the help.