Don’t insulate before an audit
I hate to use the word "never," but I'll make an exception here: *Never* have your attic insulated without first getting a home energy audit. You may think, "Of course he's going to say that. He's a HOME ENERGY AUDITOR," and you'd be right. But think about it. Insulating an uninspected attic could be hiding any number of things, such as:
-- covering up exposed or shorting wires;
-- entombing dead rodents and their droppings;
-- covering up air-leakage areas in your attic that will drag the dead-rodent air into your home;
-- burying a cracked truss that could result in a fall-through accident;
-- hiding crushed or disconnected ducts.
A home energy audit will help you solve the problems in your attic. Blindly blowing insulation will just bury them.
Below are examples of attics that were insulated without air-sealing. One of the photos shows vermiculite insulation in the wall, which is a likely asbestos hazard. I also provide an example of where orange fireblock foam was properly applied at the top plate to prevent attic air from being pulled into the home, and vice-versa.