First time dad here, so I’m not sure if this hack is known by all veteran parents. My wife and I were in the car with our 3 month-old son. He wanted out of the car seat and begin telling us quite vocally all about it. We had forgotten to bring a rattle with us in the car. So we improvised on the spot: 1 empty Dunkin’ Donuts paper bag and 5-6 nickels. Shake the bag and you have your rattle! Little Zachary loved it – even more than the $20 musical, light-up thingy that attaches to the back of the seat (of course).
Perfect example of why parents are such good hackers. We're constantly thinking on our feet.