Odd behavior

My corn snake has been climbing up in between the lid of my 20 gallon enclosure. Her temps are good, and I think her humidity is good as well. (I have one of those crappy 3 dollar hydrometers that you can get at a petco) I have ordered a digital one too. She will get a new enclosure on Tuesday but I was wondering what this behavior could be about.

4:15

4:07