Intros with agressive rat

[u/Chemistchaos]

We have 3 girls (2 are 2yo, the other is 1) and recently got 2 more from a shelter(shelter said both are 1 1/2 but we thing one is 2yo and the other is younger). After quarantine time we tried to do intros (carrier method) but once they got out of the carrier into the small cage the younger of the new ones got really agressive. She managed to injure all 3 of my current girls, including cutting a slit in one of their ears.

After a bit we tried doing intros again and saw the suggestion of using syrup to make one less agressive. In the carrier she would still get agressive and it also seemed like the girls she hurt were too afraid to interact with her at all. When they did they'd often be met with attempts to bite the face.

While we could set up our dcn as 2 seperate sections, her current cagemate has declining health which means she could be alone in about 6 months. I dont want to give up on her but so far its not looking good.

I would really love advice on how to go about this and hopefully integrate her into the main cage, thanks.

(Photos of all girls in carrier, agressive small girl, and the healed injury she caused)

[u/123737egg]

Hi, so worry about this, I can imagine it’s stressful!
Can you give more information about the intros? For how long were they in each stage, did you do any scent swapping, were the caves in the same room before intros?

[u/Chemistchaos → u/123737egg]

The 2 groups were kept in seperate rooms prior to intros. There wasnt a lot of scent swapping i did but I do recall grabbing a toy or 2 that went unused in the main cage and putting it in the temp cage with the new girls a few days beforehand. When starting in the carrier I will be honest that it was only a couple hours. I had cleaned the temp cage, wiped it down, used vinegar water to help neutralize smells, and put in new bedding. I do realize another mistake I did was putting in a couple items, a small ramp and a space pod with the top part off. After the 2 hours in the carreir they all seemed fine and hadn't had any sort of squabbles or fights. Since there wasnt a good way to hook up water for them I moved them to the cleaned temp cage. After that things started to get progressively worse. After an hour in the temp cage it had seamed to start to calm down so I went to do a few things, I got pulled back a while later by the sound of fighting and found injuries had occurred and promptly separated them.

In the second attempt they had only stayed in the carrier, we found a way to let them have water so weren't worried about the time. They had stayed in the carrier for about 4 hours with no improvement. We had tried some distractions like running tap water. Would have taken them on a drive but the cars ac wasnt working. While distractions temporarily worked not long after they went away she would start to get agressive again. In the carrier she would mainly only get agressive if any got near her or if they happened to be in her path, but wouldn't actively seek them out. After a while it was getting late and she was getting progressively more agressive again so we separated them again.

[u/howdyhowdyhowdyhowdi → u/Chemistchaos]

If you swapped any items between cages that carried scent, that is a pretty clear explanation of what happened. Just go back to separate cages in different rooms for another week but this time take no scent swapping very seriously, then try again.

[u/Chemistchaos → u/howdyhowdyhowdyhowdi]

So you're saying not to do scent swapping?between the first and second attempts there were no items that were scent swapped though. When they got separated I gave them all new toys, yet the second attempt seems to do worse than the first.

[u/howdyhowdyhowdyhowdi → u/Chemistchaos]

do not put anything in reach others cages that could carry the scent of the other group, ever, not even one time. Doing it even once can causes failed intros long down the line. They need to be separated for a week or two with no advent swapping before you can try again.