18-20 year old BP, 5ft 5in, temps and humidity are perfect (Regulated with day/night cycle). Typically this time of year "she" (never had 'her' sexed) goes dormant and we don't see her for the next few months. But this is not the case this year. She last ate 2 months ago, again typical for her as we drop the temps and reduce the day cycle as winter comes.

We feed medium live rats when she starts to look for food. Oh, I should mention she is in a 400 gal enclosure - we have created a habitat as close to her natural environment as possible. Several hides (Basking, warm, cool), two pools of water (again, one on the hot side, one on the cool side). We feed her when she starts to hunt, usually once a month (except in the winter months, last winter she went 5 months without eating with no loss of body mass). After 5 years in this enclosure we are very aware of her behavior, by looking at how she is moving we can tell if she is hungry, about to shed, hot, cold, stressed, etc. Its all subtle differences in how she moves her body and head.

But she isn't going dormant, she isn't hunting, she isn't basking, she isn't 'scratching/rubbing' -- she is soaking. For 4 days now. Twice I have gently coaxed her out of the water, but she will simply move to the other pool.

So something is wrong. This is not typical by a long shot. I've seen her partly soak for a few minutes, but she is completely submerged with only her 'nose' sticking out of the water. For days.

I've searched over her entire body, no mites. Nothing around her head, nothing under her scales. Perfect white belly, last shed was perfect (about 2 months ago). No pink/red/grey anywhere. No bugs, mites, etc in the tank - I've searched for hours. The kicker was last night I cooled her enclosure to 68F (For about 2 hours), expecting her to move to bask. Nope, refused to leave the water. Usually when we open the lids she is very aware and does like any good BP and tries to escape. She won't leave the water.

So - she is not too hot, no mites, eyes and body look perfectly fine. Last time the bedding was changed (cyprus), like every time, it was washed and baked to 180F (Baking 200 lbs of cyprus is a LOT of work).

No exposure to any other reptile (us or her)...everything looked perfectly normal until 4 days ago.

What am I missing here?