My grandparents once told me about a story about witches that would come at night and drown babies or not drown but suffocate them.
In Mexico in Oaxaca it is said that there would be green lights in sky in those would be the witches that would come at night. They wouldn’t have a specific purpose or reason but usually that is what parents would be worried about. This is why it is supposed to be important that you don’t leave your babies alone at night because if you do leave them alone The Witches would come and suffocate them in their sleep in the crib. The witch would come and suffocate the baby and in the morning the baby would be dead and purple as if someone had choked him. This was real this would happen way back then though I don’t know if it happens now.
The informant explain that the story brought them closer to their grandparents because when she was little her grandparents would tell her stories like this maybe to educate her on the idea of never leaving her babies alone at night. The story grew up with her because she would never leave her four children alone at night since she feared that the witches would come and suffocate the babies.
There are many beliefs of witches in Mexico and the idea that they come to either alert children or hurt them if they are unbaptized or if they’re left alone. This could also be something from Europe that had traveled to Mexico like the Salem witch trials. In the mountains of Mexico it has also been said that broomsticks and random green lights have been seen flying through the air and mountains of Mexico. The idea that we just joke babies comes from the fact that a lot of babies would die because of sudden infant death syndrome and Mexicans would come up with an explanation that has to do with religion and witchcraft. Clearly sudden infant death syndrome didn’t appear to them that it was due to Suffocation from a blanket.