Dehydrated or Underweight Boa?

[Kaitlyn]

Hey I’ve had my boa from a hatchling and I’ve never seen her skin crease like this I’ve always been worried she doesn’t drink water but she’s never creased up like this but I’ve also seen that it could be under weight. She is 3 almost 4 years old hypo red tail boa I was told she doesn’t need a humid environment except when she is shedding and thus far it has worked until a couple weeks ago I noticed she was getting crinkly I hav recently upgraded her to weaned rats every 10 days or so and she takes them no problem I’ve read other forums to see which symptoms best relate her but I’ve seen mixed reviews so here’s my pictures of her. HelpAlso the creasing is mainly near her head\neck