Why do people sleep at night? not at day...

I think its cause it is dark, it seems more natural to sleep. I sleep during the day only because I am used to working a night job. Plus I like walking at night when it is cooler in the summer time.

my dear just conditions force people to sleep at night but if you were born found people sleeping during day u would b asking it there other way ...but n way there are people who don't sleep night but only sleep day here in Africa what about that my friend kearkear

Haha, I think that is because humans are not nocturnal and not like bats. Haha I guess I am just not informed much about this behaviour, but logically you would not have much stuffs to do at night.

Despite I know lot of people who sleep durring the day becausethey have to go to work at night, majority of people and - to some extend, some animals and insects too - sleep night. Why? Well, some species of animals and insect are equiped to see when is no light - in darkness, night. But most of animals - including humans, only can see (propperly) when day light is "on". So they will do whatever is to do while natural light is on. Sure, humans always used knowledges - for example the making of fire - to make light after dark so to extend the time they stay awake. So, this is a way to do things we (humans) were used to do since stone age or before.

daytime are environment's best for humans visible to the naked eye rather than nighttime.... daytime lessen the criminals (or other bad influences) that roaming around compare to nighttime.... that is a 2 out of 101 reasons why people do sleep at night and not in a daytime....

It's cheaper, if we sleep during the day we are wasting natural light, and we would have to turn the lights on all night. Staying awake during the day and sleeping during the night helps us saving money on our electric bill.

I read somewhere that back in like the 1700's, I can't remember the time frame exactly, but middle class europeans would generally wake up when the sun came up go to bed when it was down but then wake up again at 11/12pm and fall asleep an hour or two later. Apparently, that schedule seemed to fit their natural rem pattern. Now, the way society is mostly everything is done on a 9-5 basis so the only time to sleep is at night. Which sucks...lol