I just recently got some house plants for my new house. my cats love them because they think they're toys. however, they play a little too rough and are chewing and shredding the leaves. I've tried to be firm with them to let them know that they aren't toys, but now they just wait till I leave the room to play. I was wondering if there is anything that maybe I could put on the plants to keep them from ruining them. or any other suggestions of what to do would be greatly appreciated. Please help