Corn snake help?
 

I've had my cornsnake for over a year now. He's about a year and a half old, just moved on to eating rat-pups.
But recently Ive been having a bit of bother with him. He's very aggressive/deffensive. I cant tell the difference I'm afraid.
If I ever go near his tank during the night he'll hiss at me like a rattle-snake would. I just got him out of his tank for feeding and he striked out at me and managed to bite me. It drew blood and now I am very shaken up. He's bitten me before but that was my fault. I picked him up too soon after him being fed, I lost track of time.
What could be causing this change in behavure? He's not been this aggressive towards me before. Usually if someone other than myself holds him he'll try to get away and come back to me, but he's never had a problem with me holding him.
He's not shedding so I dont know whats wrong :/

Yeah sounds like he's got snake aids....

Snaids?

Sorry OP, can't help.

Yes! Snaids!

Or it could just be having a bad man period?...

How often do you feed him? Could it be that he smelt the rat pup on your hand and mistook it for food? thats happened to us.

I feed him every 2 weeks. I have a reminder on my phone cause otherwise I forget. He could have smelled it on me, but that wouldnt explain the rattling whenever I go near his tank at night.

He might be just a bit stressed. Try putting putting something in front of the vivarium and just quickly check on him every now and then. It doesn't sound like any medical problem since he's still eating ok. If the whole de-stress thing doesn't work then you should get him checked out at a vet just to make sure.

ETA: Also put some new hiding places in so he feels more secure.

Sounds like one of two things to me:
He's become sexually mature. He's just frustrated because he doesn't have a mate.
It'll pass. when the mating season is up.

It's either that or he wants to prepare for hibernation. If you have a heat lamp in the tank it'll be keeping him warm and active when his instincts are telling him it should be getting cold and he should be getting ready to sleep. So he'd getting frustrated again.
I don't know if corn snakes hibernate. I know some species do.

I think the mating season for corns is in march time, and corns don't hibernate since they're from the south east of America.