My year old female didnt change slow down at all last year as a baby, she stayed up and ate like there was no tomorrow. But this year for the last month and half she really slowed down, she will go under for weeks without an appearance and nothing changed at all heat or humidity wise in the tank. I even tried upping temps and stuff like Drayvan said and nothing. I even did like you and put an extra light on top and still nothing. I got worried and brought her to the vet when she first started thinking something was wrong but she was just reacting to the changes in the air pressure and stuff. If she she goes into full estivation I will let you know in the new year how it went.