In the mediterranean its different.
As Africans live in costraints they know that there is no possibility of getting a life unless they make it to Europe. If they remain in their African country of origin, they know that they will die. So attempting to make it to Europe is a better chance.
They migrate across the sub-saharian regions as they pit-stop in towns and villages.Every stop is done to regenerate not only physical energy but also to work for food and money.
It takes them more than a year to get to the countries that have shores on the Mediterranean. Some in Algeria, some in Libya, Morocco and Tunisia. They know that they have survived a journey through the desert that had shortened their numbers due to lack of food and dehydration. Many are dead in the sands and rocks.
Now its Europe. Its warranted that if they would like to get a boat, they must work for about six months up to a year to save up $1000. and thats per person. and even if you have the money, there is a long waiting list.
More of them die from sickness and malnourishment. Some are also killed my ruthless employers.
The boat trip is not exactly what any one imagines. The old wooden boat chugging towards Sicily is packed to almost triple its maximum capacity with scores of people of different nationalities and with merely a foot between the boat's edge and the waterline. There is the risk of capsizing in bad weather, engine failure causing the immigrants to be stranded for days. Most of these Africans never saw the sea so they cannot swim. Its easy to drown.
And thousands are feared to have drownded considering that at least a boat a day leaves African coasts.
Sorry that was a bit off-topic. We were talking about fences right ?