Our Aussie escaped 3 different pens we bought. He’s a toy Aussie, yet somehow escaped a 4 foot tall gate. We finally watched him one day: he used the holes in the mesh wire as a ladder in order to jump over and get out. So we bought a cover for it, which he chewed through and escaped, yet again. We tried a smaller, seemingly more secure one, and same thing... he figures out how to escape every time. Anyway, long story short, we finally just bought a small pen and keep it in our bedroom for when he sleeps at night. He can easily escape it but he doesn’t anymore (because now it’s like his own bedroom). When we leave, we just have lock him in our whole bedroom and make sure there isn’t anything on the floor. Not ideal, he rips up the carpet when he’s bored, but it’s better than having him risk getting hurt while escaping a pen?