When Rome was still a new city, the Etruscans attacked and forced them into the fortress on the Capitoline Hill. Apparently, it was almost impossible for an attacking force to get up the side of the hill, but the Etruscans managed it…at night. It was quite likely the most critical night in Roman History.
Only problem for the Romans was that their dogs were all asleep (as were the “guards”). So, naturally, it was left to the geese (!) to see the intruders as they came over the wall. The geese started honking and woke up the Romans, who were able to fight off the Etruscans and eventually win the war.
Unfortunately, the war was not yet over. The Romans were still beseiged. So they ended up killing the dogs and eating them, rather than the geese. I mean, if you have to decide, you keep your best guards til last, don’t you?