I feel your pain! When Trevor was a kitten he pushed a depressionware candy dish off a kitchen shelf. You never saw a kitty move so quickly in your life! He scared the you know what out of himself. There was glass everywhere. This was a dish that had belonged to my mother for years. I have since learned to place those types of things in my hutch (behind closed doors). The other thing that makes me crazy about them is my inability to have any kind of floral arrangement in the house. They don't knock them down intentionally but they pull the flowers right out of the vase and occasionally that causes the vase to tumble! At times I have put flowers on that very same shelf (it is very high up!) but I have to watch it carefully. At night when I go to bed I have to put the flowers in the laundry room (again behind closed doors!) since nighttime is michief-time!! I am amazed at the strenth of your little ones, especially since they are so light. Trevor weighs 20 lbs. so I imagine he could probably push my microwave off the counter if he wanted to!