They are smart
I wouldn't be surprised to see that your dog has escaped the crate. I do not need to crate Duffy given that she behaves properly inside and has a large yard outside to play but I came across some of her tricks not to be locked without chance of going somewhere.
First of all the gates. She learned how to open them when she was 5 or 6 months. She simply bites the lock, opens it with the mouth and then walks backwards thus opening the gate. The first time this happened I thought that I did not close it properly. Then I understood but, in any case, it took me a long time to understand how did she manage to open the gates by herself. Now I have them locked always. In principle, even outside, she would not get into trouble but better safe than sorry.
Then we have the fence in the stairs. This fence is placed in proper position with a sort of ropes which are tied in order to keep the fence closed. I only close it at night so that Duffy does not go upstairs from where she can not leave by herself. She climbs the interior stairs but she does not descend them and has to do so thru the outside. Madame Duffy quickly understood about the ropes and she tried hard to chew them in order to loosen them. She did not succeed on this. Then she went to plan B. When the fence is open I use to leave that sort of ropes or cables, as you prefer, on it. Duffy simply removed them (and this is not an easy task given that it involves pulling three times to remove it from the orifices) and hide them. When I noticed I had to revolve all the house looking for the ropes and, worst, with Duffy looking at me like if she was having fun for what she was seeing. I don't leave the ropes on the fence anymore!
Boxers are really smart kids. You gotta love them!
