I have a 1-year-old California Kingsnake that I have had since June. Nagini has always been a very good eater, eating 1 small mouse weekly and has never missed a meal. The last time he/she ate (I do not know the sex), was 9/15/2013. I feed snakes regularly at my place of employment so I know it is not uncommon for a snake to go a week or more without eating; however, Nagini has never missed a meal in the year that I have been exposed to him/her, not even during a shed; therefore I am slightly concerned. He/she is in a 20-gallon tank (planning to upgrade to a 40 soon) with temps on the cool side between 70 and 76, warm side is about 80 to 85, except over the warm side hide, which ranges between 84 to 90. I am using a 40-watt blue light on the warm side during the day and a 40-watt black light for night. I have an undertank heater, which brings the temp inside the warm side hide to about 97. Cool side hide is about 72. His/her overall appearance and demeanor have not changed. Eyes are bright and clear, scales are shiny and black, extremely active. I cannot see any thing physically wrong with this snake. No mites. No ticks. I am at a loss as to why Nagini has stopped eating. I have tried warming the mouse in chicken broth, but to no avail. I can tell you that I live in the Northeast United States, so temps have been fluctuating a bit lately. I should add that I did not use lighting during the summer as it was warm enough not to need them, but the undertank heater was on during the summer. If anyone can give me some advice, I would greatly appreciate it. Thank you.