At what age did you start leaving your dog/puppy's crate open at night? Or do you still close it even though your dog is grown? The reason I ask. Last night DH went to bed early. As soon as Jax saw DH going to bed, he went and got in his crate. Since I was staying up, we left the crate door open. Jax came out to the living room around 2 AM and I took him out. When he came back in, he went back to his crate. The door stayed open until I went to bed around 3:30. I'm wondering if it would be okay to start leaving the door open full-time, but at the same time there are things I wouldn't want Jax to get into at night while we're sleeping.