foreach $type (keys $allanimals) {
  my $num_of_animals = $allanimals{$type}->count_collection(); # A method in Animal::Colelction
  foreach $animal ($allanimals{$type}->get_animals()) {
     ## Using methods defined by the Animal interface
     ## But implemented in the Animal::Llama, Animal::Camel, etc subclasses.
     my $name = $animal->get_name();
     $animal->feed();
  }
}