How'd the Shepherds Know?

In reading through the text this afternoon, I had some questions concerning the shepherds.

The angel of the LORD tells the sheep-herders that the Messiah has been born in Bethlehem, and they'll know him when they find him because he'll be in a manger. You've got to wonder if the sheep-herders cocked their heads at that one. "He'll be in a what?" shouted the skeptical one back at the angel!

Obviously a manger is not a normal bedding source for babies - even shepherds know that; one wonders if the shepherds wondered what kind of Messiah is found lying in a manger. Wouldn't a Messiah be born into royalty? What kind of manger-bound Messiah baby is announced by an army of angels? I'm sure not much of what was announced made sense. But they went, out of curiosity if nothing else.

Here's what I want to know: how'd they know where to find the manger-baby? It's night time, it's really chilly in the hilly city of David, so the shepherds aren't going to find Jesus laying around outside. If he was in a cave, how'd they know which cave? How many caves did they have to look in before they found one with a baby in it? If it was a barn or stable, how many did they have to look through? Did they just keep looking till they found the manger-baby?

I think that Joseph and Mary gave birth in a house of one of their relatives, but since they were still considered unclean, they were forced to stay in the animal storage part of the house (the only entrance being through the living room). If this were the case, how would the shepherds know which house to go to? Did they keep knocking, asking if there was a baby inside the house laying in a manger? That would've got some odd looks.

However it worked, they eventually found what they were looking for. They spread the word throughout town, and everyone was amazed by what they heard from the raggedy sheep-herders. We're not amazed by the story because we think it's perfectly normal for a baby to be born and then placed in a manger. Think about it: what are the odds that the moment the shepherds found THE house, that the baby would be in the manger at that moment. Do you really think that Mary placed the baby in the manger as soon as she could, and then left the baby there for as long as she could? I really doubt it. Mary would have held the baby, fed the baby, cuddled with the baby, let it sleep in her arms. If she wasn't holding the baby, Joseph would be. Why leave a baby in a manger when it could be held? It really was a miracle that the shepherds arrived at the rare moment that Jesus would have actually been in the manger.