Imagine leaving your family and travelling to a new country you don't have permission to enter on your own.
That's what thousands of children are doing to escape hardship and war in places like Afghanistan.
Some are sent by their parents and others get separated from their family on the long and dangerous journey to Europe.
These findings are the result of a report by the United Nations which is worried about Asylum seekers.
They say there's been a massive increase in the number of children from Afghanistan travelling illegally across Europe alone.
Afghanistan is one of the poorest countries in the world. Years of war have torn it apart.
There's little money around and lots of people - including kids - want to leave and start a better life in Europe.
Every year thousands of children make long and dangerous journeys alone, in the hope of ending up in the UK.
Walli Ullah is one of those kids. He says he left Afghanistan because of the bombs in his home city of Kabul. He says he wants to live in the country because "it's a good country."
Last year nearly four thousand children from Afghanistan asked for permission to start a new life in Europe.
One year on, that number has risen to six thousand. Although experts are concerned the real amount is much higher as kids could be worried they'll be sent back if they try and enter a country officially.
To sneak into the country, kids often hide in lorries and boats - which isn't allowed and is also very dangerous.
Aid agencies say that more research is needed to find out more about the increasing number of kids who are going through such hardships for a new start, and that European countries need to work together to keep them safe from harm.