It is easy to identify by its loose lumpy form and fluffy or granular texture.
Asbestos attic insulation identify.
If the insulation is in batt form there is nothing to worry about it is loose fill insulation poured loosely into wall stud cavities or joists that are problematical.
However asbestos can also be found in some forms of wall and loose fill attic insulation as well.
There are many different kinds of wool like insulation that are man made and do not have asbestos but if your attic insulation looks like wool than it is best to be safe and have it tested by a professional.
If you notice that you have insulation that is falling apart in your building have a professional inspect for asbestos.
Loose fill insulation comes in a variety of materials.