You can save money on your utility bills by insulating your attic.
Batts are made of fiberglass (which can make you itch). They come unfaced -without paper; faced -with paper on one side; or in an envelope which protects you from the itch. You can lay the batts either between the ceiling joists, or across them.
The idea behind insulation is to create a dead air space. The insulation should be fluffy, not packed down.
Blown-in insulation comes in compressed bales which are opened into a blower. The blower is basically a fan which moves the insulation through a long hose. You aim the hose throughout the attic and blow as much insulation as you want. The deeper the insulation, the more money you save on utilities.
Whichever method you choose, BE CAREFUL. Do not step on the ceiling. Walk on top of the joists. It may be easier to take a couple of boards to the attic to stand on.