Male rats having problems

[cherriolovescherrios]

Recently I picked up four boys who I found on this site and brought them into my home. The owner claimed they were 8 months old, but based on size, I'm guessing they're more like 5 months old.
I had decided to introduce them to my cage of 6 boys, who have always been easy to introduce and very sweet and friendly. I have never had a problem with these boys; they don't hurt each other, and introductions have always been quick and easy (I can introduce them in a day, and it's fine).
Like I had expected, introductions went fine on the first day, and they ended up staying in the same cage for the night, and then permanently. I watched them closely for the first few days, and there were no problems.
After a few weeks, recently, there has been more squeeking coming from this cage, and they have been bothering each other a lot more. I can't pin point which rats are the ones bothering others, but where the 6 boys before had never had a problem, I can only assume it's one or more of the four new boys.
My boy Stanley, he's about 8 months old, recently had a bite mark below and above his eye (the eye is okay). These boys never have been bitten before. Stanley has seemed more timid now, and I had a hard time getting him to come to me, which isn't normal.
I noticed two of the siamese boys fighting at one point, but there are three in the cage, and I couldn't tell which two it was from far away. One of the newer boys is siamese, and Stanley and his brother Manny are also siamese.

What my question is, should some or all of the new boys be neutered, simply put in their own cage (I haven't seen these four bother each other), or could they just be going after Stanley because they don't like him for whatever reason?

I've had a cage of 11 girls where two were picked on, and they were removed for their safety and happiness. One of them was old, and the other had a head tilt. Stanley however is perfectly healthy, and Elliot, another boy in the cage, does have a head tilt, and he hasn't been bothered.

For now, I closed off the door to the top half of the cage, and the four new boys are up top, and the six older boys down below.

 

[mamarat]

You had only one day of intros? I would start new intros and watch the boys how they react to each other. I would go for at least a week on neutral ground and take it from there. Good luck with your sweeties.

 

[jorats]

I am assuming you have a Critter Nation cage or Ferret Nation cage because you are able to close it in half. So that means 10 males in a CN is a lot of testosterone! And they are all at that very peak age of being hormonal and stressed. Count yourself lucky that nothing worse as happened. Meaning...they are good rats if they haven't squabbled more than that.

The bite near the eye is a defensive hit. Meaning... Stanley was being the bully and the new resident was defending himself. A straight out attack is always to the back/neck, the scrotum or belly. When you get a bite on the scrotum or belly, you need to remove the aggressor. That is downright wrong, and means business. BTW, Stanley has every right being a bully to the young new bucks. They need to learn their manners and the older boys are there to teach them.
But so far you are not getting any of that so that's really good. Like mamarat advises, I would restart intros all over again, keeping the cage closed in half for now and making them switch homes everyday.
If you can afford a neuter, I'd say get them all done... it makes for happier healthier rats. But, if you can't afford it, watch and see who is your bully boy in the new group, or even the old group... sometimes it takes intruders to set off the stress and turn an otherwise stable rat into a bit of a meanie.
If you like, you can keep describing your intros to us, on this thread, I can help interpret them and we can find out who your trouble child is and also find your alpha in the group.

 

[cherriolovescherrios]

They had been together for about a few weeks before this behaviour began... I think they're introduced. How would reintroducing them work, if they already know each other?
I've only seen a problem with Stanley. I haven't noticed any marks on any of the new or old rats, besides Stanley.
The six boys that were originally in this cage are usually really good with new rats. They sniff a little, and show a bit of dominance, but they easily settle down and eat or sleep together. I have play dates with my boyfriends 5 males sometimes, and I set them down on the ground, and they act like they already know each other well, even if they haven't really met before.
Stanley is more of a submissive rat in the cage, and I don't like how he began seeming timid.
Usually if any rat had a problem with a new cagemate, it would be Ruffles. I got him when he was 8 months old, and he had lived alone until then. It took five rats to find one he liked, and two weeks to introduce them, but ever since then, I've been able to pull off one day introductions with all rats in the cage.

 

[mamarat]

Sometimes problems only come up after a couple of weeks of intros when all the rats are comfortable with each other. Then their true character comes out. You write the boys are already separated so it would make sense to restart the intros since they are not living together anymore. Watch them and you will see if anyone needs more socializing or even maybe a neuter.

 

[jorats]

That's what how I read it too... you closed off the cage so now they are separated, this means they need introductions again. Some rats don't introduce fast and need time to adjust.

 

[shhtephanie]

I agree, starting intros again would be the best thing, especially since you now have 6 boys in only 1 half of the cage.