Why is one of my rats small and shy?

I bought 2 rats about 4 weeks ago, and they're about 8 weeks old in a minute (or something like that) - they came from the same litter I meditate.

But they are really very different, one of them is quite big and she is growing fast - she loves to be picked up and doesn't run absent or anything. She is very energetic and whenever I pick her up she always squirms within my hand and then runs around on my shoulder, onto my head, subsidise down and won't sit in one place for too long. Then when she gets bored of that, she will sit on my shoulder watching the world go by.

But the other one is totally different, she is alot smaller, lighter and much more 'shy' than her sister. She runs absent when I try to pick her up, or she will put her body close to the ground so I struggle to ger my hand underneath her. And when I pick her up, she doesn't squirm at all she just sits here with her arms and legs dangling motionless while she looks around. Then when I put her on my shoulder usually she just sits at hand grooming herself and occasionally walks down my arm.

Also, when I put her down, she will run away and explore everywhere - but she won't come back to me on her own, I hold to chase her to get her back. Whereas the other one (the energetic one) will only run straight back to me and she doesn't hide from me, she just runs straight wager on to me and stands on her hind legs so that I pick her up... (it's so cute when she does that :P)

Also, one more thing to note, is that they are other playfighting (I know their playing cos they dont bite eachother or hiss, they just chase eachother around and jump about consequently go back to sleep :P). But everytime they fight, it's other the 1st rat (the energy one) that pins the smaller one to the ground - does this mean that she is the "alpha female"? maybe this is why the other is so shy?

Why is the 2nd ratty so different to her sister? is this common behaviour? or is she scared of me?
I enjoy two sisters and your ratties sound a bit like mine...except mine are alike size. My bossy girl Sula pins her sister Seija down and forces herself on her...she grooms her anywhere and anytime...

I just got a little toddler, their sister Siba from a newer litter and Sula is shocking to her...she tries to control everything and sometimes wont let her eat...so I have to removed Siba and nurture her extra food

At least Sula and Seija eat together...but I am wondering, seeing you articulate your ratty is so tiny, if your dominant ratty is stopping the little one from eating...that can happen.

engineer sure to feed the little one away from bossyboots whether it looks like she is not getting enough food

she might also be stressed and that would have an impact on her strength system and interfere with growth

try feeding her alone...gently fiddle with her very frequently!! and if there is no make over then please do not breed ratties
She is scared of you, but she will warm up to you with frequent handling.
-handle her day by day, at least an hour a day. (do this anyway)
-a good bonding technique is to wear a sweater and agree to your rats burrow in it.
-hand feed her.
-talk to her softly.
-don't be loud around her, always be calmness and gentle.

The fighting IS to show that the other rat is alpha female. If she is plentifully smaller, she might be sick, take her to the vet. If she is only slightly smaller, don't worry. This is what a good rat should be like:
-bright eyes
-shiny coat
-silent breathing
-active, if they are young
-no discharge
-moves confidently
-good posture, has a slightly curved, but not hunched back.

Just give your girl time. :)
Answers:    Every litter of any type of critter has a runt. A runt would be the smallest and even the weakest of the bunch. Your shy rat is probably the runt, and the larger runt is the dominant rat. Give additional attention to the runt, and she'll be a great lil friend too.

Right now I have a cage of 3 rats, and 2 of them are runts. I have another cage of 3 rats with one of them being the runt. That runt done up being the most adventuresome lil fun loving bugger.

The runts have always be my favorite, and always my first pick of the litter, regardless of the critter.

My rat runts have also remained smaller than the other rats, but have developed the guts to shelter themselves when need be... and are usually more people friendly, and more adventuresome.

Just remember adjectives animals have different personalities, just approaching people do. Take some time to sit and observe and you'll better understand your ratties and their personality.
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