Sudden Aggression

Question
Hello, I have had a sudden problem. I am a major animal person, but this is my first time dealing with rats. I got my male (un-neutered) rats about 2 months ago when they were probably around 6 weeks old. I worked with them, handled them and allowed them time to run around outside their cage in my room. Shortly after getting them they started fighting, they were young, although not from the same litter. One rat appeared to get hurt a few times (I consulted a vet in this case), but I kept an eye on them and gave them time. The other rat appeared to be the aggressor most of the time. Eventually it seemed to clear up and I figured it was just a stage. Weeks later they seemed to tussle once and a while but no harm was being done. Recently I have noticed a few cuts on both rats, presumably from fighting, and separated them. Even the rat who had been up till now unscathed had injuries. A few days I let them out and this rat would not let me pick him up, or catch him, squeaked and squealed when I did and bit me hard several times. This happened repeatedly. I am baffled, he is normally more skittish than my other rat, but also more adventurous. I have changed nothing about myself or their environment. The experience made me quite a lot of distress, he is obviously terrified, but I have no idea why all of a sudden this occurred. I apologize for the lengthy message, but I wanted to ensure I was giving the appropriate information. Please help me if you can I am finding a shortage of reliable rat information on the internet. My once lovable pet will not even take his favourite treat from me after the experience. Thank you for your time,
Sincerely
Rachel

Answer
You can check out my personal rat site, sandyscrittercity.com for all the reliable info you need about rat care.  

I do have to ask, where did you get your rats from?  This is a very important question.  pet store rats are unfortunately the rats that tend to have more problems with aggression and illness because they are not bred for good health or temperament.  It is even more of a problem if they are not from the same litter.  A well bred intact male should be able to get along with a pack of males if bred right but if not, they may be aggressive toward other males, wanting the alpha role.  You can have the aggressive rat neutered of even have them both neutered.  This makes a huge difference. If not, you may need a second cage to keep harmony.  I have had to do this in the past when I would rescue rats, not knowing anything about them and taking the chance that they would get along, I ended up with four males living in separate cages.  I get my rats from reputable breeders now but I hate to tell people NOT to go to pet stores or to rescue because all rats need loving homes.  Its just a risk though when you buy from these places and can be a drain on your bank account when you least expect it having to pay for neuters etc....  Female rats dont usually have problems with aggression but if not spayed, they end up with mammary tumors at the age they hit menopause, another bank account drainer, which is why I steer away from females because I know you have to spay at a young age to try to avoid tumors as much as possible and this is a risk for the young rat too, not just about the cost, and finding a skilled vet to do the job right is also another obstacle.   The things we do for our pets.  LOL  The money I have spent not only on pet rats but cats and dogs alike, I could have paid off my house and bought two cars paying CASH for both.  But its worth it:)