People migrate to urban and developed countries in search of better employment, more opportunities, a higher level of education and a better life. Nearly 3% of the world's population does not live in the country where they were born. The United States has the maximum number of permanent immigrants. Due to immigration it becomes difficult for countries to maintain their population. Population density is also increasing, which makes it difficult to manage a country with such a large population. It is also known that overpopulation is found in developing countries rather than developed countries due to lack of awareness, lack of family planning, less education, etc. Migration has created an imbalance in the population density of the world at large. It is also said that in the next 45 years the population in the richest countries will decrease more and more and that in the poorest countries it will increase immensely. some of the reasons are that the population in developing countries consists of many young people between the ages of 15 and 30. So the fertility rate is very high and increasing every year. furthermore there is poor education and a lack of information and awareness on family protection and planning which contribute to the increase in births. It is difficult for humans to discuss reproductive control, perhaps due to shyness. Furthermore, many parents are not very open to their children talking about these things, as a result there is a lack of information which leads to unplanned fertility.