Mouse starts biting for no reason

Question
QUESTION: Dear Natasha,

I have a pair of white mice, brothers, about a year old. There is Skinny and Fatty (names for obvious reasons). Skinny is the aggressive one - he's the biter and he barbers himself regularly. He is the more curious one as well, and will be the first to explore anything interesting. I have disciplined him to stop biting, so he doesn't attack unless provoked repeatedly.

Fatty, on the other hand, always does nothing but sleep and eat and run around when he's being chased by Skinny. He's the complacent one and never minds strangers touching him - until now.

Nowadays, whenever I pick Fatty up he will bite my palm. It was gentle at first and then started getting hard although no blood has been drawn yet. He seems healthy (aside of an infected eye) and still behaves the same as before - except when it comes to people picking him up. I don't know where he got this bad habit from and how to stop it. Can you help me?

Cheers,
Vivien

ANSWER: Dear Vivien,

The main reason for a mouse to begin to bite is if it is in pain. You say Fatty has an eye infection- he is being treated for that? When you hold him, press gently all over his body to see if there is a spot which makes him squeak or flinch. Watch to see if his behavior has changed in any other respect too. Does he sit hunched over at all? Does he move even less than he used to?

Another reason to start to bite would be mental trauma of some kind. It is possible that something traumatic happened- even if you did not see it happen, such as another animal or a loud noise or someone mishandling the mouse- which has stressed him out. Mice are pretty delicate psychologically, and something can happen to change a mouse's personality for many months or even for the rest of its life.

When you say you disciplined Skinny for biting, how did you do that? Mice should never, ever be punished for anything. The only form of discipline that I feel is safe and works is the teensiest little tap on the top of the nose just as the mouse goes to bite. It is not to hurt him- lighter is better- but it is sort of an insult, as I understand it. I have found it work well for nippers. Not the front of the nose but the top.

You want to make sure there is no cause for the biting before training against it, though- if he is in pain, it would be cruel  to tap his nose for doing what he is supposed to do.

As for protecting yourself, and possibly to train him out of this, put a bandaid or piece of tape on your palm before you pick him up.

I was handling a rescue bunny recently and I completely duct taped my hands and forearms : ))

Do let me know what happens.

Squeaks,

Natasha

---------- FOLLOW-UP ----------

QUESTION: Dear Natasha,

Thank you for taking the time to answer my question! You mentioned mental trauma, which I think might be the case. I've recently moved a lot, could that be the reason (change of environment)?

Also, as for discipline, I've always given the tap on the forehead. Skinny knows he's being naughty because after he bites he makes eyes when he sees the finger coming for his nose. But Fatty's never been tapped until now really.

I've dosed Fatty with cotton bud dipped in salt water for his eye infection, hopefully that should work out? I've tried giving yoghurt as well but nothing much happened although they love it.

Also, how do I check for other areas where Fatty hurts? He's a very active mouse and won't sit still in the hand.

Thanks again for answering my questions!!! I really appreciate it.


Cheers,
Vivien

Answer
Dear Vivian,

Yes, if anything happened during a move- cage fell or even tipped, loud noises, anything-- if he is a very sensitive mouse, you never know what it was. Most mice adjust to new situations pretty easily but to specific events not so well.

Salt water isn't enough if it isn't clearing it up. He may need antibiotics. Can you get him to a vet? You need to find one which specializes either in "pocket pets" or "exotics."

Can you kind of massage him while he is captured in your hand? Otherwise, you may need someone to hold him for you. The way to hold a mouse still is to put it on your right palm and hold gently but firmly to the very base of its tail right by its rump, with the other hand.

But of course if you are going to the vet anyway, the vet can do it. A trained vet should know how to hold a mouse. S/he may use the scruff of his neck.

Best of luck to poor little Fatty.

squeaks,

Natasha