I've had my captive born Northern Pine snake since he was 1 month old. He was always a good natured snake, and healthy. He liked being held. Now he is 3 years old. And just recently he hisses loud and acts wild when held. He is still healthy and eats well.I notice if I hold him for awhile, he does calm down some.But he was never like this. I had more than one person tell me that the reason is that he is now at mating age and it is now mating season. Is this true? If so, will he get over this by summer? Or when? Nothing has changed with his housing, or anything. What is his problem?