When you put crabs in a bucket, you do not have to worry about them escaping because if one tries to climb, you can be sure that one or more crabs will drag it back into the bucket. The same mentality has been displayed by African countries towards one another. The "Ghana must go" campaign in Nigeria in the 90s and the recent xenophobic killings in South Africa puts the crab mentality of Africans in focus. Africans, it seems, do not like to see citizens of other African countries do well in their country but that is a wrong mentality.
We have to realize that if one African can escape the shackles of poverty, it is for the continent's good not minding where the person is from. Rich people like Aliko Dangote and others have not only been useful to their native countries, they have impacted Africa as a whole.