Slimy Babies

I was watching a movie last night, and there was one of those scenes where someone has a baby, and it's all touching and nice. However, looking at that slimy baby got me thinking. How do they cast for these parts? Do people willingly toss their newborns into Hollywood productions? Here, take my baby and slime it up good. I suppose money helps, but still, it seems odd to me. I mean, here's this baby, new and impressionable, and probably pretty happy to be free from the womb. Naturally, he/she would probably not be that pumped to simulate the miracle of life all over again. Sure, the baby's job is pretty easy. Lie around and let them cover them with goo like they've been slimed by a ghostbusters' ghost, but i wonder how confusing that must be. Their tiny little minds thinking, "didn't I just d0 this? Come on!" I suppose it's better than one of those rebirthing exercises. At least, the slimy baby movie role will pay for college.