There are many reasons why these rats with white fur are out numbering These rats with black fur it mostly depends it could be due to natural selection ya know Like i mean it could be

Due to natural selection right? So i'm just assuming right
I mean like these rats could live in like a place where there more white stuff like snow so these white rats would have a better chance of survival for the white ones to survive because it's harder to see a white rat in snow instead of a black one right

Another reason could be genetic factors - if the gene for white fur is more dominant or advantageous in certain environments, the white rats may simply have a higher rate of reproduction. Additionally, human intervention such as breeding for certain traits or habitat destruction could also play a role in the imbalance. Ultimately, there are many factors at play and it would require further research to determine the exact reasons for the disparity in population numbers.