Loose Skin?

[krisym]

I am new to snake (and ball python) ownership, so I am unsure of the cause of the problem. My ball python Bean has what looks like loose skin that folds when he is curled up. I would greatly appreciate it if you can help diagnose the problem or if I'm concerned over nothing.

Skin: http://imageshack.com/a/img538/6215/XGvOn8.jpg

Enclosure: http://imageshack.com/a/img538/9550/WeOBiB.jpg (Sorry about the links. For some reason it's not letting me load images.)

Some background info:

I've had Bean for about 3 weeks. The guy I got him from only had one hide on the hot side of his tank and no way to measure humidity (I'm currently using my skink's humidity gauge to check his tank but I'm about to buy a new one for him either tomorrow or Thursday). He has an UTH, the warm side about 89-94 and the cool side from about 75-80. He didn't specify exactly when he shed, but an estimate would be about 4 weeks ago. He said he feed him every 3-4 weeks and didn't specify what he feed him and in what quantity. He also was aggravating Bean by tapping him on the head (which Bean really didn't like). He didn't know if he was WC, CH, or CB and said that Bean had bit him in the previous week.

Bean is 13 years old, weighs 2.4 lbs, and is approx. 3.5 ft long. I feed him every 2 weeks (only two feeding so far), the first time feeding him 4 large frozen mice, second time 2 small frozen rats. I have made a temporary second hide for him out of a cardboard-esque basket until I go to the store again. He has bitten me twice but was completely my fault because I handled him too soon and didn't allow him time to get acclimated (he still is fairly uncomfortable with me). I added a fake vine for him and replaced the repticarpet with newspaper. I'll mist the enclosure occasionally too, probably about once a day. His enclosure is about 3' x 18". I fed him 4 days ago and since then he's stayed in the makeshift hide and hasn't come out except for sticking his head out the entrance.

Is his skin folding because of dehydration, food, shedding, or another cause? Or is it something that I shouldn't be concerned about? Also, does this warrant a visit to the vet (I might take him just so he can be checked out anyways)?

Sorry for the long post, and I appreciate any help that I can get. (Also if there's anything I'm doing wrong with Bean please let me know).

[dr del]

I'd say shedding.

Raise the humidity to about 60-70%.

[krisym]

Thank you!