Why is it not advisable to sleep under the trees during nights?

Friend in India many peoples says that we should not sleep under trees during night time because there are devils and Ghosts on tress but i too think it is not true because in night time tress release carbon di oxide and this gas is harmful to human body.

hhmm are you sure as tree's and plants absorb carbon dioxide and give out oxygen if trees are giving off carbon dioxide they are giving off a green house gas ?? and we should cut all the tree's down which obviously isn't the case as we need them to produce oxygen. Some evergreens do give off carbon dioxide in colder weathers as they generate their own heat though not enough to be felt by us tho. I would be more scared of sleeping next to my partner in bed as us humans give out carbon dioxide everytime we breathe out.

That is good to know. I do not ever even sleep outside, but if for some reason I would have to, I will avoid sleeping under trees. That is a very interesting fact.