Getting enough sleep is vitally important for mums and dads, but so many of us wake up in the morning and feel like we've hardly slept at all.
Now, a new study has found that we might just have inherited the "wrong" gene, as scientists say they can now explain why some of us need more sleep than others.
People who carry a variation of a gene called ABCC9 ideally need to sleep half an hour more every night than people who do not have the variation, the researchers found. Apparently one in five Europeans has the gene variation.
The study was carried out by scientists at the University of Edinburgh and Ludwig Maximilians University in Munich.
Dr Jim Wilson, at the University of Edinburgh's Centre for Population Health Sciences said: "Humans sleep for approximately one-third of their lifetime.
"A tendency to sleep for longer or shorter periods often runs in families despite the fact that the amount of sleep people need can be influenced by age, latitude, season and circadian rhythms. These insights into the biology of sleep will be important in unravelling the health effects of sleep behaviour."
If you now feel like having an early night but find it difficult to get the little ones to bed, have a look at these top tips on how to speed up bedtime.