I have two crates, in use; a normal bolted one and one with an up and over door. From a puppy, Teddy has been able to get in and out of the dropped, but not pushed into slot, door (I have some action photos somewhere, showing his progress into the crate to steal Izzy's dinner). He has since got out now and then and I've assumed it's because I didn't press the door down properly--until this Tuesday.
As the bolted crate was in the hall and I'd treated the carpet, I put Joly and Teddy into the up and over crate and got Izzy and Monty ready for a walk. No sooner had I reached the door, but Teddy was with us, tugging on someone's lead. Joly was still sitting in the crate, with the door dropped down, but not in its slot.
Knowing that I had closed the crate firmly and being unable to use the other crate, Teddy was put back, the door closed firmly and a heavy computer monitor placed in front of the door , to prevent it from rising----and we went for our walk.
When we got back, there was Teddy waiting by the door and Joly was still in the crate. He'd not only opened the door, but moved the monitor over 30cm away. Now I know the grey crate is not Teddy proof, so it's crate with bolts---until he susses those out , too..
Barbara, Monty, Joly and Teddy.