There are three most common rodent species found in homes in both urban and rural China: the Norway rat (Rattus norvegicus), the roof rat (Rattus rattus), and the house mouse (Mus musculus).

The Norway rat is the largest, with adults weighing 200–500 grams; they are strong swimmers and burrowers, preferring to live on the lower floors of buildings, in basements, and in sewers.

The roof rat is medium-sized and an excellent climber, often found on upper floors and in attics of buildings.

The house mouse is the smallest, with adults weighing only 10–25 grams; it can squeeze through gaps as small as 6 mm, making it the most common and most difficult indoor rodent to control.

House mice reproduce extremely rapidly — females can produce 5–10 litters per year.

Species identification is very important for control — different rodent species have different habits and food preferences, and the placement strategies for traps and baits vary accordingly.