Layla does this too, she has since I can remember, and she's almost 11 months old now. I've tried teaching "drop it" with her toys for months but she just isn't getting it, she seems to only learn things (like sit, lay down) when i have the toy and she wants it. When she has something she shouldn't have, she either runs under the couch, or runs behind my drumset, and goes in between and around it if i try to reach at her. As soon as I say "treat" or she hears crumpling of the bag she'll drop it immediately and come to me. But if I move towards the thing she had before she gets a treat, or even after she gets it, she'll run back and grab it again. It seems like she's just doing it to get treats.
I could ignore her but she loves underwear, and I have a male classmate living with me. That's just awkward. And if I ignore her when she gets a kleenex or paper, it doesn't matter. She just wants it to rip it up anyway. So I end up cleaning a whole floor full of ripped up paper.
I don't know what to do anymore