if ($this.night == --$christmas && !(my $houseStirring) 
   && my $numMiceStirring < 1) {
 bless my $cat;
}

foreach my $child (@beds) {
   if ($child.inBed) { $child.sugarPlumVisions++; }
   else { $child.stocking = 'coal'; }
}
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Updated to check for general stirring in the house, and to make sure all the kids are asleep in their beds.