Our dog Kirby runs to the front of the house barking, whenever he suspects the approach of a delivery person.  This is the same behavior that he exhibits, when he suspects that a squirrel is in the front yard.

Upon hearing Kirby bark, I run to the front door hoping that a package has arrived.  This usually involves drooling on my part.  I do this whenever Kirby barks and boy am I sad, when it turns out to be a squirrel.