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Pet Rats/Aggressive young doe biting and lunging


Hi Debbie,

My partner and I bought our 4 little girls at a large pet shop on the 5th March this year (7 weeks ago) and we were told they were 6 weeks old. Two of them were obviously younger as they were noticeably smaller. Being pet shop rats they were very skittish initially but we persevered with playing with them every day and feeding them from our hands. During this period they have had to visit the vet 3 times as they have all had chest infections.

When we were first given the baytril to administer we were informed that we had to syringe the medicine directly into their little mouths. They were incredibly skittish still and did not like to be picked up never mind being held whilst we attempted to syringe  a very bitter medication into their mouths. We carried on doing this for the 10 days and this was a terribly traumatic time for them. When we were told they had to go on antibiotics again we researched administering medications to rats and discovered ways to hide it in treats which was less traumatising for all of us.

Unfortunately one of the girls has become more and more frightened of us to the point now where she has bitten both of us, drawing blood and causing quite nasty injuries to our hands. When we play with them or during feeding she will try to attack our hands and when we sit outside the cage she lunges at the cage wall and attempts to build a barrier to separate us - she pulls the toilet tubes to be placed up against the wall and adds the small toys and anything else she can find to build up her barrier. It's getting to the point now where I am on the alert when I put my hand in the cage to play with the others in case she is around and I think it's also affecting how the others are reacting towards us.

Together they are happy and play well. If I try to remove her from the cage to clean it she squeaks and attacks me and then runs away. I have to wait until she hides in the tunnel and then lift the tunnel out gently and place her in the temporary cage we use whilst cleaning the main cage. I have tried removing many of the hiding places as the cage is very big and it is very difficult to interact with her. But she is becoming more and more aggressive and it breaks my heart to see her living in fear like this. Can you please help us? We would really appreciate your expert opinion.

Kind regards,

Hi Amanda,
Did their respiratory infections respond to the Baytril?  I always recommend the first antibiotic tried be amoxicillin, especially in young rats, because respiratory symptoms are often caused by secondary bacteria, not mycoplasma, and Baytril is not usually as effective for the secondary infections as amoxicillin. Amoxicillin also tastes much better than Baytril! I recommend secondary infections be treated for at least 2-3 weeks. So, are they still on antibiotics?

What you need to do with the scared one is Trust Training. See the article of that name on my website at on the Rat Info page. You'll have to take it very slowly with her, and work to motivate her with the food to willingly allow you to interact with her.  Obiously none of them were very well socialized to begin with, and she may just have an extra suspicious and wary personality.

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Debbie Ducommun


I can answer any questions about pet rats, but you will probably be able find answers to simple questions more quickly on my website at If you have a life-threatening emergency you can try calling me at 530-899-0605. I am not usually on the computer on the weekend.


I have been "The Rat Lady" since 1985 and am recognized as one of the world's experts on pet rats. I have 3 published books and already answer lots of questions about rats daily.

President of Rat Assistance & Teaching Society

I am a monthly columnist for Pet Business magazine, and my writing has appeared in other magazines. I have 3 published books.

BA in Animal Behavior

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