Researchers have discovered that nearly two thirds of the UK dislike putting the lights out before they hop into bed, while 36% regularly get the feeling someone or something is in the room with them.
As many as one in five, or 20%, of the 2000 adults polled by sleep experts - Bensons for Beds - said they regularly check under the bed for lurking mosters and close the cupboard and wardrobe doors before getting into bed.
A further 17% admitted ot sleeping with a light on most nights of the week.
According to Bensons' research, not everyone fears a 'monster' is under the bed. The average response in the survey suggests that the average adult wakes up at least twice a month feeling scared that something 'creepy' is hiding in the room.
48% of people in the survey said they have an overactive imagination, which leads to them feeling scared and frightened of the slightest sounds and noises.
In fact, 22% of the nation confessed they do not like to have their feet hanging out from underneath the covers in case 'something grabs it', while 25% of adults believed they have seen a mysterious shadow in their bedrooms.
Interestingly, it was women who were most likely to suffer from fear of the dark. In the survey, 53% of women said they are scared to be in the house alone, compared to only 25% of men.
Bensons for Beds Chief Customer Officer, Henry Swift, said: 'This research highlights that some of the fears and insecurities we have as children, stay with us well until adulthood.
'Whilst it’s sensible to double and triple check doors and windows are locked securely, there is probably little need to check the wardrobe or under the bed for monsters, but at some point we have all felt nervous during the night when we hear a floorboard creak or can’t make out a shadow clearly.'
According to the research, when it comes to worrying, the most common time for adults to become alarmed is 2:30am.