No. Mothballs are a pesticide for controlling clothes moths. According to Federal Pesticide Regulations, all pesticides (including mothballs) must be used in accordance to the product label.
Mothballs contain 100% active ingredient, and are hazardous to young children and pets. Studies have linked naphthalene, the active ingredient in moth balls, to diseases such as nasal cancer. Besides, who would want to have their home smell like moth balls?
The photo below, is an example of the reason this product was not called bat-balls. Bats have been roosting directly above this box for some time (it is covered in bat droppings).
Photo - Bat Droppings Piles on Top of Moth Balls.
Attempting to control bats with moth balls is ineffective, illegal and will just put you at risk.