Why do babies cry when they want to sleep?

Pfft. Get me too far away from a bed and coffee at the same time for too long, and I’m damned cranky, too.

Babies don’t know what they want; they just know they are uncomfortable. And they express their discomfort – whether wet, hungry or tired – by crying. Some babies are easier to sooth and more placid and some are fussier. The fussier ones cry more.

Imagine you could only make one sound. Imagine you beep, imagine you honk your horn, whatever you want, just imagine it.

Whenever you want something to change, you make that sound and hope someone is listening, because you can’t get very far, don’t know how very many things work, and can’t change your situation by yourself. So you make your sound, wait a bit, make your sound louder, look around, and then just let your one sound go on until it’s fixed.

That’s a baby until about 9–12 months old. Then they’re frustrated that you’re not picking up on their increased vocabulary of three sounds.

What the jellies above said! And just to add, I would imagine the baby is crying, quite simply, because they want to be in their mother’s arms. I would imagine they want and need that contact and reassurance before they can fall asleep.

How do you feel when you’re over tired? A bit cranky, right? They do too. And they get over tired much more often than we do.
Toddlers do the same thing. Parents learn to understand the cry, and the “acting out” behavior as signs that the child is tired, even if they deny it. I can hear it in other people’s children. And it drives me nuts when they keep demanding to know what is wrong with the kid, why is he or she being a “brat’ an crying about everything. Cuz he’s tired, lady.

Yes, what everyone else has said, and, to follow up on @Dutchess_III ‘s sharing. It takes a MASSIVE amount of energy to be a growing infant. At no other time in our lives will we grow at that fast of a rate, except maybe during a, much later, adolescent growth spurt. This is why babies and teenagers often require so much sleep. Anytime one is in a major growth spurt the body needs extra rest time.

Teens are so weird. They run at top speed for 19 hours a day, then sleep for 2 days, if you let them.

I was never that way, @Dutchess_III. All my life if I fell asleep – even if it was for a couple minutes – I was good for 4–6 more hours.

I think they are tired and fearful at the same time. Once held in mothers arms listening to moms familiar heart beat they seem more at ease.
Remember all they ever knew before getting born was being in a warm environment with the steady rhythm of a heart and intestinal noises. Nothing but warm liquid on their skin. No outer sensations or strange noises or lights. No hunger. No itchy poop, or pee that burns. You could sleep whenever you wanted. You didn’t have to wait till you were exhausted.
Once born, that comforting noise is gone. There are new noises. Sometimes your bottom is dry and other times its wet and itchy. Your food doesn’t just come to you. You have to cry for someone to notice you are hungry. Being hungry sucks. You could kick and thrash all you wanted to get in a comfortable position and you don’t get twisted up or cold because your limbs slipped out of your blanket.
I wonder, how is they don’t cry more. Oh, and lets not mentions, sniffles, and boogies. Boy do they hate it when they can’t breath. Before even oxygen was taken care off and they never got constipated or had the runs.

^^^I wonder how far back newborns can remember, and for how long?

Babies would use texting if they could, but they don’t have the manual dexterity to do so.

Seriously – what other means of communication does a baby have?

Well, I understand the question though, @elbanditoroso. They can’t feed themselves, so they cry when they’re hungry. They can’t cover themselves so they cry when they’re cold. But they can put themselves to sleep. So why don’t they just go to sleep instead of crying?

The answer is, something is preventing them from going to sleep.

Because they haven’t developed logic yet. They’re uncomfortable, but they don’t know why.

My earliest memory was falling out of my crib and landing on a throw rug on the hardwood floors that acted as a super slide runner and shot me across the room and, literally, underneath my parents bed. I was about 18 months old. I remember my mothers face leaning down looking at me under the bed and exclaiming something I don’t remember. haha

Probably “dumbass!”

^^^ LOL I don’t think dumbass was part of my moms vocabulary in 1960.

It’s not a “phenomenon.” Something is a phenomenon when there is no clear, obvious explanation for why something happened.

I watched couple of my littlest grandkids all day yesterday, 1 year old Cooper and 3 year old Zoey. Cooper was super fun and happy all day, until just before my son came home. He got really mad and fussy. Before I could diagnose him, my son walked through the door, and I commented on it.
He said, “Oh, when he gets all enraged like, that for no reason, he needs to be fed.”
I paused. The way he said it, some small inflection, cause me to say, “You mean, I’m running a zoo?.
He laughed and said, “Pretty much!