When the screen was lifted, if there weren't the number of expected snacks the baffled hounds stared at the piles much longer.
This counting skill could have once helped them work out how many enemies they had in a pack.
And they even have different barks:
Away from their owners they do high-pitched, single yaps.
The doorbell sparks off a lower and harsher bark.
Play barks are high pitched and come in