[cypher]

It may just be because it's getting colder now, although most hams will have the odd night when they don't stick to their normal routine & I doubt a bit of extra carrot will have done any harm (just check he didn't stash it somewhere!), it is common for syrians in particular to get up later as winter approaches.
Keep an eye on him just in case there's something else going on, if he doesn't come out of his own accord or doesn't appear to be eating & drinking normally a quick health check never hurts.