Need Rat advice - new cagemate?

[Downamongtherednecks]

One of my DD's rats died of a respiratory infection (even though we only use the paper bedding, never wood) and her surviving cage-mate is very unhappy and needs company. I have found a rat rescue place that has 70 (!) rats to rehome - someone turned in 200 to them in one go. Our existing rat is hooded, and about 2 years old, female.
a) what should be look for in a cage mate ie age, temperament, type etc?
b) how do we go about trying to get them to tolerate each other?
Any suggestions would be gratefully received. DD thinks her surviving rat is "eating her feelings" though, tbh, it has always been greedy and cuddly. Thanks in advance.

DSD has 5 rats, she had 2 brother rats then one died so we got him cage mates. We put the 2 new rats into a separate cage and put that near the existing rats cage so they could sniff each other but not close enough together that they could attack eachother. We waited a day then introduced them all in the bath tub together, after some forceful grooming from the older rat to the younger ones to show he was boss they seemed to get along. Then they were introduced in DSD's bedroom where they played then all put in older rats cage with him. We did the same steps a few weeks later when we got 2 new rats again. However you can't but shove them all in the cage together as older rat will probably attack defending her territory, older rats are harder to introduce to other older rats so baby rats is your best bet. Some rats cope well on their own however If she had a cage mate she won't be used to it so would reccomend a friend for her. Your best bet would be 8 week old ry so she doesn't feel threatened and your best bet will be to get 2 rats so that if older rat dies the younger one won't be by itself.

Thanks Jade I think the bath tub idea is great - kind of crowd control. Yes, I think two is a good idea, or we will keep facing the same problem of having one left over. I was worried that baby rats might get killed by the older one, and I dont think DD could take more death!

I was worried that dsd's male hooded rat would hate new rats but he was fine with them. If they start to fight them you could put them in separate cages.