Why does this call to `getNoise` use the base class implementation and not the subclass implementation?

The problem

My understanding was that we could achieve polymorphim by making getNoise virtual in the base, and then overriding it in any subclasses. Then via a vector of pointers, we store the address of the base classes which are used to call methods on such as getNosie below.

Could anybody tell me why my code doesn't do this?

The code

#include <iostream>
#include <vector>
#include <memory>

using namespace std;


class Animals {
private:
    std::string noise = "None";

public:
    Animals() = default;

    virtual ~Animals() = default;

    virtual std::string getNoise() {
        return noise;
    }

};

class Duck : public Animals {
private:
    std::string noise = "Quack!";
public:
    using Animals::Animals;

    std::string getNoise() override {
        return noise;
    }
};

class Dog : public Animals {
private:
    std::string noise = "Bark!";
public:
    using Animals::Animals;

    std::string getNoise() override {
        return noise;
    }
};


class AnimalsContainer {
public:
    std::vector<Animals *> animals;
    Animals *front;

    AnimalsContainer() {
        Duck duck;
        Dog dog;
        animals.push_back(&duck);
        animals.push_back(&dog);
        front = animals[0];
    }

    ~AnimalsContainer() = default;
};


int main() {
    AnimalsContainer animals;
    cout << animals.front->getNoise() << endl;

Expected output

I'm expecting

Quack!

But I'm getting

None

"std::string noise" should only be declared in the base class, not in the subclasses. Set the noise value in the constructors of the subclasses instead.

Why dont't you use pointers:

Duck* duck = new Duck();
Dog* dog = new Dog();
animals.push_back(duck);
animals.push_back(dog);

Instead of

Duck duck;
Dog dog;
animals.push_back(&duck);
animals.push_back(&dog);

You can then destroy them on the destructor:

~AnimalsContainer() {
    for (Animals* a : animals) {
        delete a;
    }
}

If you really need noise string "none" in the base class.

Of course the raw pointers are for simplicity, you should maybe use smart pointers.