Angry Corn

Question
i have owned a corn snake for 4 years from a baby, it has been wonderful to have him a absolute delight although he is rather big, a few wierd things happened over the years like, he went off food for about 3 months but thats fine now. Recently he has become very agressive darting from each side of the viv, tucking him self in the lip of the lid on the vivarium he also has become agressive towards me when i go to clean or put water in for him. He becomes very alert as soon as i go near the viv and when i open the sliding doors, also i picked up my phone that was situated next to him and he struck at the glass. Help me i'm getting nagged by the mum in to selling him and i don't want to.

Answer
Ryan,
   The corn snake has as many temperments as colors. It is not unusual for a snake to become alert later in life. The good news is that they dont get very big and that a bite is not venomous or particularly painful. Tell your mum that your snake has a rare personality and that makes him more valuable!