What are the short term effects of inhaling moth balls?

a friend of mine has a small dollar store and had a snake problem she heard that mothballs would help keep them away so she spread them throughout the inside of the store but i am concerned the store smells so bad of moth balls it hits you in the face when you open the door and some of the products i have bought there smell like them to can this be hazardous to my health or her customers the store doesnt have good ventalation and how long could it take to get rid of them i am so worried she could have poisoned herself and her customers any helpful information or suggestions?