Help! My dog started eating my used pads and panty liners!?

I have a female black lab, a little over a year old. She has never been a problem when it comes to the trash, except getting out an occasional used kleenex (she likes to rip them up). We haven't had to worry about putting lids on our trash because she just stays out of it. Until recently anyway.

A friend of ours brought his 2 black labs over and they ran all over the house, including our bedroom and master bathroom, plus the regular bathroom. I didn't realize at the time they could get in the bedroom because my husband told me that he had closed the door. After my friend and his dogs left, I found used pads chewed up and strewn across the floor in the master bathroom and bedroom, and a few on the floor in the main bathroom.

Since then, my dog has been digging them out of the trash! She learned this behavior from them, obviously, which is really irritating. Is there anything I can do to get her to stop? I will be switching to garbage cans with lids, but I would like to know if I can get her to stop.