Weird behavior from 2 year old beardie

Lately my baby (Tippy) has been begging to come out of her enclosure during the day (which is fine we have her out almost half the day most days) but the last few days shes been just running around the house looking for a cold dark place to sleep.. she'll explore a little bit only to find a cold dark place such as under the couch, behind the toilet on the cold tile floor, or really anywhere cold and dark. This behavior has just recently started & I'm kind of worried. For example - We take her out of her enclosure at say 2 o'clock in the afternoon after feeding and giving her some time to digest, she will run around free roam in our beardie proof basement suite for about a hoag hour or so then just go to sleep somewhere cold and dark, if I leave her she will sleep ALL DAY LONG. just worried. Any help would be very much appreciated.

Mine does the same thing basically--- not sure why -- he will sit on the back of the chair for a little while and then head for his favorite place which is on the chair behind a throw pillow in the corner of chair-- and he would sleep there all day if I let him --- 2 hrs and his time is up- I put him back in his tank -- there he will bask and be awake-- till lights out around 7 PM or so -- I dont know why that is
Karrie