sub add_animal() {
   my $type = shift;
   if($type == "Llama") {
      my $newanimal = new Animal::Llama;
   } elsif {$type == "Camel") {
      my $newanimal = new Animal::Camel;
   }
   push (@allanimals, $newanimal);
}

my $zoo = new Zoo;
$zoo->add_animal("Llama");
$zoo->add_animal("Llama");
$zoo->add_animal("Camel");

$zoo->count_animals();

__OUTPUT__
There are 2 Llamas in the zoo.
There are 1 Camels in the zoo.