Mara won't stop sudden, unprovoked biting-- possible neurological/hormonal issue?

[jorats]

SqueakingJellybean Would you mind updating your post as to what happened to Mara? Did this behavior get worse or better?
I am asking because my two year old male rat suddenly began having the exact same thing happen. He will be chittering and happy one minute and the next second he is puffed up and attacks my hand. He was also a rescue and has always been pretty jumpy with bad eye sight. However, he has NEVER bitten before or shown any aggression towards us, until now. And it's completely unprovoked!
He has randomly bitten/attacked my hand twice now within the past two days when I've tried holding him and he has now drawn blood. I can't think of anything that we've done wrong with him. He was always such a happy little rat.

Hi, when this happened to my rats at an advanced age, it was due to either pain or neuro issues. A rat with a pituitary tumour can all of a sudden become aggressive. But a rat in pain will act out as well. I would get him checked out.

 

[SqueakingJellybean]

SqueakingJellybean Would you mind updating your post as to what happened to Mara? Did this behavior get worse or better?
I am asking because my two year old male rat suddenly began having the exact same thing happen. He will be chittering and happy one minute and the next second he is puffed up and attacks my hand. He was also a rescue and has always been pretty jumpy with bad eye sight. However, he has NEVER bitten before or shown any aggression towards us, until now. And it's completely unprovoked!
He has randomly bitten/attacked my hand twice now within the past two days when I've tried holding him and he has now drawn blood. I can't think of anything that we've done wrong with him. He was always such a happy little rat.

Mara is still a bit munchy. She's drawing less blood lately and has nipped a couple of times with no blood drawn at all (yay!), but she can still go from friendly to Empress Puncture Wounds in a heartbeat.

One thing we've noticed is that she doesn't like little hand movements. I suspect it has something to do with her eyesight, but doing something like patting a lap or drumming fingers on the bed is a sure way to end up leaking people-juice. It may also come from overexcitement-- sometimes she just doesn't know what to do with herself, so she bites. Milo used to pounce/play/groom/wrestle/dance when he was overexcited. There's still the chance it could be neurological, but she hasn't shown any other signs. I'm hoping her behaviour will continue to improve with age. Even if it doesn't, we'll give her as much love as she'll let us. I couldn't bear the thought of giving up on her (or giving her up).

I'm sorry to hear about your wee guy. Given his age, it might be something neurological.