"Are you my mother?"

Is anyone familiar with this Dr.Suess book?  Basically, it's about a baby bird that falls out of the nest right after being born.  His mother is gone finding food, so the baby sets off on a journey to find his mother and get home again.  He goes around asking other animals and ridiculous inanimate objects (airplane, bulldozer, etc.) if they are his mother.  In the end, he is returned to the nest and all is well with the world. 

 Anyways, Mac displays this weird behavior every time we are on a walk that reminds of us this book.  Each time a car passes us - especially if it is slowing down to turn or stop at an intersection - he perks up and starts pulling toward the car.  He cocks his head like he wants to say, "Do I know you?  Are you my mother?"  I swear if we let go of the leash, he would run up to the driver's door to try to meet who is inside.  Or maybe he would just run after the car because he is convinced he has some type of emotional connection to this giant machine.  (Obviously entering traffic would be a bad thing, but he is totally oblivious.)

As a result, every time a car approaches Blake and I know to tighten the leash.  And we always laugh and say, "Are you my mother?"