One of mine did that saturday. He killed it, started to eat it, and with about 3/4 of the mouse hanging out of his mouth, he retracted into his hide (the kill was pretty close to the hide, so he was never completely out).

After getting back in, he took a bit longer than normal to swallow, but all is well. I was surprised, because he typically ate outside the hide.

How long has yours had it in the hide?