In those days there was no king in Israel. Also in those days the tribe of Dan was searching for a territory of their own to live in, since no permanent territory had been assigned to them among the tribes of Israel up to that point.
References for Judges 18:1
The Danites sent five men from their whole clan, strong men from Zorah and Eshtaol, to spy on the land and explore it. They told them, "Go explore the land." So they went into the Ephraim highland as far as Micah's house, and they spent the night there.
When they were in the area of Micah's house, they recognized the accent of the young Levite. They turned in there and said to him, "Who brought you here? What are you doing in these parts? What is there for you here?"
"Micah has done a lot for me," he replied to them. "He hired me to be his personal priest."
They said to him, "Ask for an answer from God so we can know whether we'll be successful on this trip we've taken."
The priest replied to them, "Go in peace. The LORD is watching over you on this trip you've taken."
So the five men journeyed on until they reached Laish. There they saw that its people were living without worry in the same way as the Sidonians, undisturbed and secure. Nobody held back anything in the land, so no one had to hoard. Yet they lived far away from the Sidonians and had no dealings with anyone else.
References for Judges 18:7
When the men came back to their relatives at Zorah and Eshtaol, they asked them, "What did you find?"
"Come on," they replied, "let's march up against them! Indeed, we've seen the land, and it's very good. Right now you're doing nothing! Don't hold back from going and taking possession of the land.
When you arrive, you'll come upon a secure people and a wide-open land, because God has given to you a place where nothing on earth is lacking."
At this, six hundred men from the Danite clan at Zorah and Eshtaol set out armed for battle.
They marched up and made camp at Kiriath-jearim in Judah. This is why the place west of Kiriath-jearim is still known as Dan's Camp today.
From there they crossed into the Ephraim highlands and came to Micah's house.