I am pretty sure that this is the very same Black Rat Snake that I rescued (in a half-frozen state) back in November 2010. I brought it in the house, placed it in a terrarium, and let it warm up, and housed and fed it until May 2011, when it started showing signs of restlessness. [id=294785410]
In August of 2012, it made a return visit, was still very placid and did not object to being handled, and I posed it on a large glass Pyrex insulator for a "glamor shot" ;-) [id=349017933]
Well, today, it has returned once again, I found it sunning next to the front porch, looking fit and even fat, perhaps gravid with eggs, or perhaps it just ate a copperhead! (Black snakes will kill copperheads and small rattlers, and eat them - apparently they are immune to the venom).
Once again, it let me approach up close, I took a few pictures, then it slowly crawled under the front porch.
If it is gravid, then perhaps she was looking for a safe and sheltered place to lay her eggs.