Mine used to escape from the smallest of spaces in the crate. Below the door near the floor there was a small space, not very big, and I wouldn't have believed she could escape from there but she did (I caught her one day.) I cured this by turning the crate upside down and it worked. Check your crate very carefully. They can squeeze through the smallest holes sometimes and could get stuck.
Good luck with your little escapologist.
Hugs Shirl x x |