Compare cell to cell in previous row

Maybe?

Sub am_hawk()
Range("B2").Select
Do Until ActiveCell.Value = ""
    If ActiveCell.Value <> ActiveCell.Offset(1).Value Then
        Range(ActiveCell.Offset(1, -1), ActiveCell.Offset(1, 3)).Insert
        ActiveCell.Offset(1).Select
    End If
    ActiveCell.Offset(1).Select
Loop
End Sub