Mayor's mouse lives in Sri Lankan forests. The lowland subspecies is described as having flattened, spiny dorsal fur and a white underside.
In the subspecies Mus mayori pococki, the dorsal fur is fulvous brown and flattened into a spiny texture, while the underside is white. Its slender, finely scaled tail is about as long as its head and body.
In a Sinharaja forest study, the population of this species showed only small fluctuations and tended to be higher in wetter periods when fruits were abundant. No seasonal movement among the sampled habitat types was detected.
An extinction-risk assessment has not been added yet.