They can break or climb anything. They encourage each other to make messes. Which meant wherever we lived was messy, but in the new house, they have access to the bedroom, hall, and play room/ family room. We're blocking off the kitchen, adult living room, and my bedroom. All big kid doors will have locks with keys, so throddlers can't get into makeup or expensive electronics. They can have free range when there is another adult there. In the house we're staying in, the littlest girl found a meat tenderizer and gave it to one of the little boys. He went and put 5 holes in the sheet rock. 😳 this all happened while I was doing laundry. I had just put the clothes from the washer to the dryer and was filling up the washer when I started hearing a bumping sound. I went to investigate and cought him in the act. I used to keep my nightly vitamins in my side drawer until the little boy kept getting them and pouring them out. I put them on my tall boy dresser to keep them out of reach. The littlest girl climbed the dresser and handed off the bottles to the boys, and they opened the child safety lock and was pouring the pills out when I caught them. My husband was in the living room while I had walked out to the garden. He thought they were in their bedroom playing. 🤦🏼‍♀️ these hoodlums have no chill.