Mine do the same thing, or at least I hoped it was only 'that' but I have since learned, and I TOTALLY BLAME THE COCKATOO!!!!
When they hear my truck pull up, they all come waiting by the door, OR if they hear the lid of the snack can snap off, they come running from the 4 corners of the earth! They learned that the truck means I am home and I will soon be out with snacks to check on them.
I know DEEP in my heart that the reason they come running is because they realize what a wondurfool stoopendus, awesome daddy I am and just absolutely adore me, and it isn't just because I bring food.......
ok ok, ill go take my meds now

Aaron