[Gypsymama]

I have two male rats that my son bought from a pet store 3 months ago (he quickly lost interest in them and they became mine). No idea of their exact age but he was told they were less than a year old when he got them.
Once they got used to their new environment they were both friendly, like to climb on me, accept treats from my hands, and have no problem with me reaching in the cage. I set up a free roam area for them and sit on the floor with them and let them climb on me etc. Maybe a month after setting up the free roam , one of them attacked my hand and bit me very badly. I had to put him back in the cage to clean my wound so playtime was over!
Then maybe a week or two later he was sitting on my lap and trying to climb in my sweatshirt like he likes to do and I reached for my shirt and he bit me again, not as bad as the first time but still broke skin.
Tonight during free roam time he attacked my foot while I was just standing there , he was latched on good and I screamed and instinctively shook my foot and when he let go I put him back in his cage.
Why is he being fearful/territorial when he’s out of his cage? And are my reactions going to make him more fearful of me and make him bite me more?!
He will also chase and pin down the other ratty when he comes out to play so the other one just goes back in the cage.

 

[stupidhats]

That sounds like hormonal aggression. How old is he, approximately?

 

[ratsbian]

Hi, considering he is going after you and his cage mate, it sounds like it may be hormonal aggression (HA), which tends to start around 4-12 months if I remember correctly. I would contact an exotic vet near you and see if neutering sounds like an option, or if there’s any other options they can offer (I think I heard of a hormonal implant option from someone but don’t quote me on that). Surgery can be a daunting option but neutering has great success in eliminating HA in male rats.

I did also wonder, before all this happened, did anything spook him during out of cage time? How is he when he is in his cage, especially with his cage mate? Does he still display dominant behavior or aggression? Do you have other animals that may startle him when he’s out of the cage? Just trying to see if maybe there is something else going on. Either way, I’m sorry you’re going through this & hopefully you can find a way to remedy it soon!

 

[Gypsymama]

Hi, considering he is going after you and his cage mate, it sounds like it may be hormonal aggression (HA), which tends to start around 4-12 months if I remember correctly. I would contact an exotic vet near you and see if neutering sounds like an option, or if there’s any other options they can offer (I think I heard of a hormonal implant option from someone but don’t quote me on that). Surgery can be a daunting option but neutering has great success in eliminating HA in male rats.

I did also wonder, before all this happened, did anything spook him during out of cage time? How is he when he is in his cage, especially with his cage mate? Does he still display dominant behavior or aggression? Do you have other animals that may startle him when he’s out of the cage? Just trying to see if maybe there is something else going on. Either way, I’m sorry you’re going through this & hopefully you can find a way to remedy it soon!

 

[Gypsymama]

Hi, he is totally fine in the cage with me and the other rat. They each take turns trying to be dominant with each other and I can reach in and move things around, fill their water and food and They both take food from my hand no problem. He’s only biting/attacking when out of his cage so I’m leaning more towards fear but maybe he just hasn’t started biting when he’s in the cage yet…
I can’t think of anything that startled him or scared him, we do have two small dogs that aren’t allowed in the rats room and the first time he bit me she was sitting outside the door so maybe he smelled her? Ferb was the smallest of the two when my son bought them and he has grown quite a bit but I have no way of knowing his age for sure.
Does hormonal aggression affect all male rats ? As Phineas is as chill as can be, just happy hanging out in his tunnel eating his sunflower seeds! Lol

 

[Gypsymama]

That sounds like hormonal aggression. How old is he, approximately?

 

[Gypsymama]

We really don’t know, as he came from a pet store . We’ve had them for 3 months and he has definitley grown quite a lot since then

 

[ratsbian]

Huh, my first instinct is that it may not be HA then, though maybe someone with more personal experience can chime in. I may hold off on out of cage time for a bit and instead reinforce bonding through treats and other in cage activities since he’s only acting this way out of the cage. When you do out of cage time, can he go back in the cage on his own or is it a separate area? He may be somewhat insecure and get fearful. I don’t know how familiar you are with rat body language but there are many resources that go over common signs of discomfort or fear that may be good to brush up on in case you’re missing something he’s trying to tell you, let me know if you need some links.

As for your question, not all rats have hormonal aggression, though it is typically genetic.

Edit: it may also be good to see about having a vet check up for him, to rule out any underlying physiological issues triggering this behavior. Brain tumors can trigger sudden shifts in behavior. It isn’t what I would jump to as a cause but it’s good to consider all the options.

 

[Gypsymama]

They have a ladder to come and go from their cage during play time and he loves it! He’ll find a treat that I’ve hidden, stash it in the cage and come out to look for more. I set up some hides for him in the play area as well. I didn’t know anything about pet rats at all when my son brought them home so I’ve been reading posts on this forum, watching rat Tik Toks and researching online. But I have not looked into rat body language so if you have some helpful links that would be great!
I can maybe take a video of him in the play area and post it on here as well and maybe you could read his body language?