plz help me my rat losng fur n gained a lot of weight only one rat not the other

Question
hi got 2 pet female rats under 1 years old ive  had them now bout  4 months and the one rat,tinkerbell has lost fur round her legs and neck head and side of back,all U can see it pink skin and has gained a lot of weight, and comes up to the cage going mad really sniffing noises at me and pushing my hand away. why?

they are both white rats half dumbo ones, the other rat rose is fine and hasn't gained weight like the other one shes the same as normal, but i know that rose down try and pin tinkerbell down and try to mate with her,which i think is normal aint sure,

please help me

Answer
Rose may be barbering Tinkerbell, which is where they are grooming them so much that they actually cut the fur as well. This is nothing to worry about, the fur should grow back in next time she molts. As to gaining weight, the simple solution is that she is eating more. If females especially, do not have a wheel to run in they can get overweight from eating too much.

There could be a bit of a hierarchy issue going on between the 2 of them, in which Roe is mounting Tinkerbell trying to dominate her, which is where the barbering also comes into play, and Tinkerbell could be showing her dominance in a more passive way by pushing your hand away and eating more, getting to the food dish first and eating more of the more fattening foods.

As long as Tinkerbell is not trying to bite or showing any signs of aggression and you have not seen any lumps or anything else of concern, then they should be fine.