Our pet rat just died early hours of this morning

Question
Tonight my youngest kids, 8, 6 & 11 are staying with my eldest daughter 23.
In August 07 I bought two male rats, brothers, they are 15 months old and between looking in their cage around Midnight and again just 30 minutes ago, one of them was laying dead and cold already on the floor of his cage, his brother sitting quietly next to him.
They have always been very close, and the one that died is the most unexpected of all. He looked perfect! His eyes were closed, his mouth closed, no discharge from anywhere, no blood, and he was the one with the big personality, more like a dog, who loved to be handled and played with, and had really sweet, almost human traits.
I'm so shocked, and other than mite problems everything has been fine.
He did have an infection in his foot last summer, but that was all treated by the vet, and got better very quickly.
He was making some strange noises on Monday night, but he periodically did this, in fact they both do, always have done, it's almost like a purring, & cooing sound, I had mentioned it to the vet before and was told that was normal?
I didn't think he was looking his usual self, they have both lost a little weight, in spite of eating well, and drinking well, I thought perhaps they were just getting a little natural change in their looks from being babies to full adults, as it has not been so significant to worry me, but now I'm not so sure? I'm so confused.
It's New Years Eve, I don't know how to tell my children, it will be the first pet death for them, as this is their first pets. They are going to be completely devastated as they love these rats sooo much, as I do too.
I cuddled him and held him for a while then wrapped him in kitchen towels, and I know this must sound awful, I have put him in a freezer bag in the freezer, I feel kind of horrible, but I want to preserve him so that the children can give him a proper burial when they come home!
I think they would feel far worse if I told them he died and I had done it without them, they are going to want to say their goodbyes, and I think it's important, what do you think?
Ironically, our pet tarantula had her first shed on Christmas eve, I was so worried she would die, it's a very risky time for these spiders, but she did fine!
What do you think might have happened? The other rat seems fine right now, but I know he will start pining before much longer. I understand it is quite hard to introduce a new male rat to an older male rat, I'm not sure what to do?
Any ideas please? Thank you for reading.
Donna.

Answer
I am so sorry for your loss. Its so hard because they only live to be 3 years, maybe pushing 4 years old, sometimes even sooner and with their big personalities, its pretty devastating. Only a rat owner can understand though. Most people think we are absolutely insane for mourning the death of a pet rat. If they only knew, ya know?

As for having him in the freezer, dont feel bad,  I have had two rats in the freezer (you wont believe this) for six months.I have lost over 42 rats over the years, losing one just three weeks ago. He was 3.5 years old and I found him laying very still, barely a pulse, and I had him put down because I knew he would never recover. It was probably a massive stroke. Had I not found him till morning he would have been just like how you found your rat, dead without any indication anything was wrong. My boy was old, but he wasnt sick at all. He is in the freezer now to until spring. So that makes three rats. Once spring comes I will bury all three but for now, they are  gently wrapped and in a plastic shoe box together. My kids call the freezer the Pet cemetary. Both are adult children ages 18 and 23 so its not traumatizing them, they are mocking me if anything....brats.  I usually have necropsies done on them and dont get them back. If I cremated all 42 I would have 42 tiny urns around the house with rat ashes in it....that would be a bit much. That said, you should not feel bad for having him in the freezer. Its fine and its also a good idea that the children are able to give him the proper farewell.
As for his brother....he may really mourn like crazy and this can be a problem. I have lost rats to a broken heart. so to speak. What it really means is that the rat mourns till they are stressed, stress causes the immune system to weaken, the rat falls ill and has no will to fight the illness and also passes away.  I have also had rats do fine. The rat that died recently left behind his brother who is also 3.5 years old and so far he is fine. I have two bucks from different litters living solo because they are both older and set in their ways. The other solo rat is my boy, Santana, who is 2 years old and he only has one eye. I cant risk him fighting with Bo, the solo 3 yr. old and possibly losing his only eye!  Bo is grumpy as it is so they interact through the cage bars and already they go at it, puffing their fur, walking sideways, spitting, hissing, slapping at each other. Its ridiculous!!
However, I have also introduced bucks to other bucks and they usually get along good but it takes time. I would watch him really good and see how he acts. You can get two new rats for him, not one, this way he wont feel like he would want to boss them as much. Not babies....but boys around 4 months old.  You can even check the shelters for rats that need homes. A spayed female would be a perfect addition. Males usually get along good with spayed females.
I have always owned male rats and prefer them over girls for two reasons. One is because girls tend to be high strung and always busy, never taking the time to snuggle on my lap. They are also prone to mammary tumors and unless you spay them young around 3 to 5 months old, they have at least a 75% chance or greater, of developing mammary  tumors after menopause, around 18 months and older.
You have a tarantula that just shed and my 5 year old jumbo hermit crab just shed too....and I was worried sick about the silly looking thing and couldnt wait till I saw his shell moving around again, which would prove he made it through shedding the exo.  No matter the species, animal lovers love their pets, this is the truth.
Finally, you asked what might have happened to the rat that passed and the truth is, he wasnt really old, but chances were he had a heart attack. Was he and his brother from a pet store? Sometimes buying pet store rats almost always promises a rat with some type of congenital defect, be it the heart or kidneys, and they pass away suddenly. Another thing that is seen in sudden death is a brain aneurysm. Either way, it was probably sudden and the rat did not even suffer.
The other male was standing guard, bidding his farewell. Some rats will actually attempt to consume their deceased rat and I get letters from people that are very shaken up after making that grim discovery, and they often think the other rats killed the deceased rat till I explain that in the wild, rats will consume their dead so they dont leave the evidence out for their predators to find their nest. They consider this a proper burial.
Anhyhow, my heart goes out to you. Please take care and good luck.