When summoned to my son’s bedroom at 3 o’clock this morning, instead of the usual grievances (“I’m hot!” “I lost Bunny Sniff-Sniff!” “My waderboddle is empty!”), he surprised me with a very calm and strangely lucid, “Mumma, how does the Rock-a-bye song go again?”

Through a succession of yawns, I explained that we don’t sing songs in the middle of the night because we are sleeping. Then I kissed him and turned to go.

“Just whisper it then,” said his voice in the dark. And after a beat, “Please?” Deliriously, I conceded.

If you’re ever tempted to give in to such a request in the dead of night, I don’t recommend it. I wound up having a nightmare in which I was pedaling up a treacherous mountain pass on a bicycle totally unsuited for the conditions. Lots of other people were bicycling with me, most of them children. Almost at the top, I heard a terrified voice say, “Turn around! It ends!”

Sure enough, as I approached what appeared to be the summit, the land suddenly fell away as though half the mountain had sheared off in one go. I barely managed to veer my bicycle around to avoid plunging into a gaping chasm of swirling clouds and nothingness. Others didn’t stop in time. The cries of children falling startled me awake.

Down will come baby, cradle and all.

I was relieved when my son woke a few hours later, chipper as can be and evidently immune to the sinister implications of the words I’d whispered to him in the dark. Children have a knack for filtering out information they’re not ready to process.

As a girl, I listened to my mother sing me the exact same lullaby. It never frightened me then, even though I was well aware of what would happen to me if I plummeted 50-odd feet from the top of a tree to the ground.

As a mom, the sheer physics of the situation breaks that bough in my mind before the wind has even started blowing.

Turns out such nascent mommy fears didn’t originate the day my first child was born. You can find their echoes threading through ancient cradle songs in every language, beginning with the first known record of a lullaby written in cuneiform script on a Babylonian tablet dating back 4,000 years.

Richard Dumbrill, an archaeomusicologist at the British Museum in London where the tablet resides, says it’s quite common to find “menacing” language in lullabies of this era: “They try to tell the child that…he woke up the demon, and if he doesn’t shut up right now, the demon will eat him.”

Well, Richard, that pretty much gets to the heart of the matter. Let’s see if we agree with his interpretation. Here’s the translation of the Babylonian script:

Little Baby in the dark house
You have seen the sun rise
Why are you crying?
Why are you screaming?
You have disturbed the house god.
‘Who has disturbed me,’ says the house god?
‘It is the baby who has disturbed you.’
‘Who scared me,’ says the house god?
‘The baby has disturbed you, the baby has scared you, making noises like a drunkard who cannot sit still on his stool. He has disturbed your sleep.’
‘Call the baby now,’ says the house god.

Yikes. Stop acting like a drunkard, Little Baby! (Is it me or does this read like the voice of someone using her infant child as a scapegoat for her own late night ribaldry? Anyway…)

Vintage engraving from the Babes in the Wood is a traditional children's tale.

Intimidating sleep tactics were not limited to the fertile plain between the Tigris and Euphrates. They ranged far and wide, featuring frightful demons of every conceivable shape and size – from Brazilian crocodile-hags and ox-monsters coming to get you while your parents are not home to Russian wolves that will “grab you by the flank” and “drag you into the woods” to Haitian man-eating crabs that have a special appetite for wakeful children.

In Scotland, it’s the parents you need to worry about. Evidently, they’ve got a habit of straight up losing their babies after setting them down to gather berries. (The origin of the BabyBjörn, perhaps?) To be fair, the Scots get points for their appreciation of nature: “I saw the swan upon the lake…I heard the curlew crying far.” But the defenseless newborn? Gonzo. “Ho-van, ho-van gorry o go, I never found my baby-o!”

But I think Iceland wins the disconsolate parent award with this sweet little ditty:

Sleep, you black-eyed pig. Fall into a deep pit of ghosts.

In other words, you’re already a goner, kid. And I’m alright with that.

Such threats are not confined to lullabies alone. Pull back the covers of any nursery rhyme and you’ll expose some very dark chapters of human history.

Remember “Mistress Mary quite contrary” who, it seemed, had some efficacy as a gardener? Well, outside the nursery she went by the name of Queen Mary I of England, known to the common folk as Bloody Mary for her homicidal streak – in particular, torturing people with “silver bells and cockle shells” and then executing them because they were Protestants and not Catholics like her.

“Pretty maids all in a row,” my foot.

And have you ever wondered what was up with the architectural instability of London Bridges? There are numerous theories about this one, including exciting 11th century Viking attacks. But the most disturbing finds its roots in the practice of entombing people, often children, in man-made structures – in this case bridge foundations – and then leaving them there to die of dehydration or starvation, whichever comes first.

Why on Earth…? To please the bridge gods, naturally, as human sacrifices are wont to do. In Laurence Gomme’s “Ethnology in Folk-Lore,” she claims when children “formed a circle and then an arch, under which each ran and was imprisoned by the others, they clearly were perpetuating the idea of a foundation sacrifice.”

Clearly. As John Kroes so aptly puts it in his “5 Terrifying Origin Stories…” article for Cracked, “Old-timey England sure hated them some children.”

All this nightmarish source material begs a really interesting question: Why do we still sing these songs? Why did anyone ever sing them?

To soothe our children – assuming they’re too young to understand, or somehow able to sever the soft, rhythmic melodies from their ominous lyrics?

To terrorize our children into good behavior? As we’ve seen, there’s a stockpile of evidence supporting this theory.

To sooth ourselves? Because maybe the act of playing out our deepest fears will somehow prevent them from actually coming to pass. Stephen King would go with this theory. The Spanish poet Federico Garcia Lorca would agree with him.

Lorca believed the main purpose of a lullaby was to express, and in turn relieve, the inevitable worries of a mother. That is to say, lullabies are basically Mommy therapy. I buy that.

Ever since my boys were born, I’ve sung them to sleep at night. On certain nights some songs just get me right where it counts and I find myself fighting back tears. Like the eve of the first time I left them for two weeks straight and I sang Gillian Welch’s “Dear Someone”.

When they asked why I was crying, I didn’t say that it was because I was praying they would have happy, full, un-messed up lives even if my plane crashed and I never returned. But that’s what that song was about for me that night… Rush little wind over the deep for now I’ve begun. Hurry and take me straight into the arms of my dear someone. It made me feel better to sing those fears out loud.

So as long as my kids keep asking for “One more song, please, Mumma,” I’m going to keep singing them, unsettling ironies be damned.