Lots of children are not getting enough rest and not sleeping properly because of technology - according to a new study by education experts in America.
It says that in some countries as many as two thirds of 9 and 10-year-olds are being kept awake because of things like mobile phones, consoles and computers.
The international survey by Boston College, says lack of proper sleep can have an impact on children's education as kids might find it more difficult to concentrate if they are tired.
In the study, researchers asked kids in 50 countries about their sleep patterns.
They found that, on average, almost half (47%) of primary school kids didn't get enough sleep.
America has the biggest problem - where nearly three quarters of 9 and 10-year-olds taking part in tests were affected by a lack of sleep.
But kids from England weren't too far behind - with 64% not getting enough kip. Ireland was also in the top ten worst countries for sleep, while Wales and Scotland weren't part of the study.
Other well-off countries like Australia, New Zealand and Finland also had lots of sleep-deprived kids.
How well do you sleep?
We wanted to know if this happens to you: do you have problems nodding off?
Are you kept awake by gadgets and games or do you find it easy to switch off and go to sleep?
Do you have you phone or computer in the bedroom at night or do your parents make you leave them in another room?
"I slept very well last night but the worst thing is waking up! Before I go to sleep I get to watch something on my iPad."
Lucy, London, England
"I went to bed at 10:00pm but did not sleep till 12:30 because my phone distracts me!"
Robyn, Cambridge, England
"I often aim to go to sleep at 10, but sometimes I forget the time when I am on my iPad/phone, which has an effect on my mood the following day!''
Hattie, Stoke, England
"I always have trouble getting to sleep and I always go on my favourite game on my iPod and when I wake my head feels really bad."
Grace, Leicestershire, England
"I slept well but stayed up late watching TV and chatting on Facebook."
Lara, Devon, England
"I never go to bed when I'm supposed to because my phone and laptop keep me up until late."
Jade, Llandudno, Wales
"I slept well last night, I just read a book before I slept."
Nadia, London, England
"I slept very well and had a dream about doughnuts."
Daniel, London, England
"I always have my iPad by my bed at night, but I don't play on it in bed, I just use it as an alarm. I still have trouble getting to sleep, but I don't think it's because of gadgets."
Katy, Wirral, England
"I don't really have problems getting to sleep because I seem to have a natural ability to drop off. There are nights when I can't fall asleep easily so I just read a book. I don't have any gadgets in my room."
Alexander, Scottish Borders
"I don't keep electronics in my room, and I usually sleep quite well."
Anna, Kent, England
"I slept ok last night but I played on my iPhone in the middle of the night."
Alisha, London, England
"I have a lot of trouble getting to sleep, I have tried getting rid of my electronics and reading but nothing works, I get probably 5-7 hours sleep each night."
"I go to bed at 10 each night but then I read on my iPod. I will turn it off between 10pm-2am and I wake up for school at 6:45am."
Chloe, Leeds, England
"My bed time is at 9.30, but I'm up so late doing homework that sometimes I don't get to bed until 1:30 in the morning!"
Cecil, Kent, England
"I go to bed at 9 but don't go to sleep until around 10 - 10.30 because I am playing on my iPad or watching TV. I do stay awake because of this, it's part of my routine."
Vanessa, Wiltshire, England
"I find it easy to go to sleep, even though my phone is with me."
"I sleep from half past eight till quarter past six I then go on my iPad until seven to watch Newsround."
Josh, Manchester, England
"I always have trouble nodding off because of my DS3 but on holiday I have no problem getting to sleep."
Kye, Bournemouth, England
"I do sometimes have trouble getting to sleep and if I've been on a screen that's very bright I will get a headache when I close my eyes."
Lucy, London, England
"My parents take my gadgets off me at night and I read a book or my parents read to me at night."
Alyssa, Lincoln, England
"I think the parents should decide if children should have gadgets in their bedroom."
Thomas, London, England
"I went to bed at half past eight but I went to sleep at nearly eleven because I was watching videos and playing games on my iPad."
Kitty, Bournemouth, England
"I wake up early and I don't spend that much time on my tablet. I only go on it until nine and I wake up at six so I have more time to wake myself up properly before school starts at nine."
"I personally don't have problems falling asleep, even though I have both my computer and a mobile phone in my bedroom, I am able to turn them off and go to sleep."
Zuzka, Prague, Czech Republic
"I always have my phone on charge next to me at night, so it is hard not to be tempted not to play on it, but if my mum catches me on it I get it taken off me."
Stephanie, Norfolk, England
"Last night I felt so tired after a long day so I just curled up and fell asleep. Although other nights I have trouble getting to sleep and it can take up to two hours for me to nod off."
"I read a book every night and don't have any gadgets in my room. Last night I slept for 11 hours!"
Beth, Stamford, England
"I go upstairs to my room at 7:30 then I do my homework till 9:30. After that I have a shower then I go to bed. I don't have any gadgets to play on as my mum takes them all off me."
Emily, London, England
"I don't have many gadgets that I use much so it's quite easy to get to sleep but I do have the occasional rough night which is hard to cope with."
Sophie, Totton, England
"When I go to bed I stay up reading a book our play on my mobile phone."
Niamh, Nottingham, England
"I do not have any electronics in my room but I do read a chapter of my book before going to sleep. Most nights I get to sleep about quarter past ten and get up at seven or earlier."
Alanna, Pontypool, Wales
"I always sit up at night and feel very tired but just can't seem to get to sleep. It is very hard to get up for school in the morning."
Name: Jodie, Kent, England
"I usually go to bed at 11 or half past 10. I do feel tired afterwards at school but I do my best. I like to stay up on my tablet computer."
Alannah, Armagh, N Ireland
"I sometimes find it hard to sleep because I can't resist a go on my iPad."
Jasmine, Castle Douglas, Scotland
"I go to bed quite early but end up reading in my bed, luckily I don't have a lot of gadgets I can play on so I'm not kept up by that!"
Erin, Somerset, England
"I stayed up until 11 last night watching TV and using the laptop. My mum says I should go to bed earlier to prepare for Sats but sometimes it's too tempting."
Jenny, Preston, England