i follow the instructions on the can and no its not out of date. i use it on a regular basis as a preventative, hence the name "provent a mite", so i allways have a fresh can on hand. the one and only time that i had a bad investation due to snakes i bought online from a well known breeder, the pam actually killed alot of them but not all. i still had live mites walking around just days after treating. i think the tiny mite problem im having now is due to thinking i had killed them all w/ pam before but obviously didn't. i read about the ivomec method in a book i have. the book says its safe as long as done properly. just desperate do kill all of the little bastards once and for all....