Answer:
-Too little space: If there are too many people, there won't be much space. New York City is an example, I suppose. In New York City, there are a lot of people. New York City is also kinda known for having some small apartments and stuff, I think. In Manhattan, there are seemingly millions of people, though Manhattan is only one borough. To do this, the space where people love is more cramped. The opposite would be more rural areas. In a place where the population is less than 500, the distance between peoples homes could be possibly miles.
-Limited resources: If everyone needs food and water, then there needs to be enough for all of them. This leads to more space being possibly needed to be dedicated to things for these, such as farms. It could also lead to it bring harder for some to get food if there's a limited supply with such a large demand, that could raise the price, making it harder for the poorer to survive. If there are more people, they might also use up resources faster and add to things like climate change. An example would be the difference between 8 gas cars' effect on the enviorment versus 800 gas cars' effects on the enviorment.
-Control and Monitering: If there are too many people, it may be harder to regulate them. If they're harder to regulate, it could lead to more crime and violence.
