In those days there was no king in Israel: and in those days the tribe of the Danites sought them an inheritance to dwell in; for to that day [their] inheritance had not fallen to them among the tribes of Israel.
"What doest thou in this place"  (Judges 18:3).  Apparently, Micah had not shared with the spies whom he entertained in his home the existence of that shrine.  We do not know why he seems to have made no mention of it, but the fact appears in the evident surprise of the spies who received all the details, not from Micah, but from the Levite.  Perhaps Micah did not altogether trust his visitors.