Ever saw a birth scene in a film or on TV and though "Gosh that baby looks old" well that's because babies have to be at least 15 days of age before they are allowed to 'work'. Ever wondered what the gunk is they put on the babies after a birth scene? Apparently it can be anything from 'Grape Jelly' to 'Cottage Cheese'. Grim. To find out more, give the below article a read... It's quite an interesting part of filming you don't often hear about.
“So you have four infants, approximately the same age, same hair color, look enough alike that they can double each other,” said Chris Riddle, an assistant director for film and television. “You use one baby for the first 20 minutes, a second baby for the next 20, etc. And if you’re doing a shot where the baby isn’t the focal point, or maybe it’s just in a crib in the background, you use a doll.”