Kitty Crack

Friskies Crispies aka Cheesy Poofs are kitty crack.   Marley has been at it again.  This is the 2nd time she has gotten onto the cupboard, grabbed a bag of poofs and chewed the bottom of the bag off to get into it.  The first time, she did it to 2 bags at once, and ate 1/2 the bags and then puked.  This time she apparently had more self control and only did 1 bag.  If she even hears me move the bag, she comes running.  She knows the words "cheesy poofs" and goes nuts when I say it.  She inhales them, I don't even think she chews them.  She is such a sweet kitty, but she will do almost anything to score.  Are these things even street legal? She will carry the bags around in her mouth all over the house.  I often hear this scratching noise coming out of her box or basket, and surprise, surprise, it's Marley trying to open the bag of poofs herself.  I think she thinks I won't notice.  Is it bad that I continue to feed her habit (pun intended)  She especially likes the cheese or the milk ones, but she isn't picky, the chicken or salmon flavors are good too.  What do they put in these things?  I swear to god they have some addictive substance in them.  There is no place safe to keep them; she knows all my hiding places.  Well, off to go find a new place to put her stash!