Answer:
Due to the growing population, people are forced to migrate to other cities, hoping for a job opportunity that pays reasonably to support their family. Being unfamiliar to a foreign city and having no capability to afford a house to live in, they tend to settle on a land they dont have legal claim. Occurrence of natural disasters is also one of the possible reason of the existence of illegal settlers. As they are being chased out of their own home that leaves them no choice. These people also experience discrimination, 'marginalisation' in other terms because of their economic status.
