Yes, this is mentioned autovivification feature.

Usually this helps, but if you feel you need other behaviour, then it's easy to write a sub similar to "exists" without that feature: 

use strict;
my %s;
sub rexists (\%;@) {
  my ($href, @values) = @_;
  for (@values) {
    return 0 unless ref($href);
    return 0 unless exists $href->{$_};
    $href = $href->{$_};
  }
  return 1;
}
print rexists(%s,qw(a b c)),"\n";
$s{a}{b}{c} = 1;
print rexists(%s,qw(a b c)),"\n";

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Courage, the Cowardly Dog.

In reply to Re: hash surprise by Courage
in thread hash surprise by smackdab

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