pet rat EXTREME aggression

Question
i have 2 male rats...about 2 years old...one is very social but would rather play and explore than cuddle. The other is VERY anti social...will TOLERATE being held...but squeaks..and bites hands when they come near him...though it is obvious he is afraid and will eat out of my hands and crawl on me if i am calm.

all this said...i have had a very traumatic night. i was playing with my 2 parakeets...(whose cage is next to the rats) and one landed on their cage (which is NORMAL)...he was walking around as per usual...but tonight..one of the rats attacked (i dont know which one)...i saw the whole thing..but they are both large white males...he bit his tail feathers and then proceeded to DRAG him thru the bars of the cage (which was not really large enough) and mauled him to death...all in about 15- 30 seconds...no provocation...and i was caught unaware as they usually socialize well...i tried very hard to save him...but one of them ripped him almost in half from  out side the cage (out of nowhere!) i am heartbroken...i have been online for 2 hours and can seem to find no information about behavior like this...(*also- the other rat was hiding sort of in the corner)...i play with them daily...feed them well...and work with the shy one every few days with treats...why did this happen?

i am so sad and confused..any information would really help...

Answer
Oh Veronica, I'm so sorry for your loss!

Male rats are territorial. They may tolerate others in their space for long periods of time, and then out of nowhere, all of the pent up aggravation comes out in violence. It sounds like you have a male that although he has tolerated these birds, has had enough of them.

It sounded like you had a horrible, just horrible event. At two years old, you can still neuter a rat, which will completely change his aggressive behavior. But, if he's already that old, (about 70 in human years), some vets won't do the surgery. It sounds like since he is getting older, and his personality is changing, that you may have a rat with traces of alzheimers in his genes.

Rats, like people, can suffer mental illness and depressive disorders. In alzheimers, the animal, or the human, start to lose familiarity. In other words, they can look at you as mom one minute, and think you're a stranger the next. It's rare that rats go through this, but it does happen. Remember, most pet rats are raised from those that were used in experiments. Hundreds of generations later, they still carry some of the illnesses bred into them, including cancers and some other disorders.

It sounds like your older boy is starting to feel his age. He may be losing sight, or smell. He may be showing signs of memory loss, alzheimers, or even depression. Some times a rat that has been sweet his whole life, will suddenly act odd if he has a tumor in his adrenal glands or pituatary glands. These create hormone rushes that overwhelm even the sweetest of pets, (and people).

If he's not harming his brother, I'd keep them in the same cage, but watch for some behavior changes. Does he eat the way he always does? Is he hiding more? Does he stay hidden when you are around? Is he reacting to noises? Light? Are his back legs moving well? Is he able to eat soft and hard foods?

Chances are the old age issues will increas as time goes on. I won't tell you the answer is putting him to sleep. I will tell you that you have to use your best judgement, and knowledge of his history to decide what you should do next.

Hang in there, Veronica. I'm sure he wasn't intentionally trying to hurt you by his actions. I hope he improves in mood over the next few days. You can add chamomile tea to his water, (change it daily), to see if it calms him down, too.

Keep me posted!

Cathe