Rats reproduce year-round in stable environments that have adequate food, water and harborage to support additional animals. About 30 percent of the females may be pregnant throughout the year in these conditions. Less favorable conditions limit reproduction to summer and autumn. Rats are color blind. The average life span of wild rats is one year.
Rats visit fewer food sites than mice.
However, rats eat much more at each site than mice. A house mouse's home range is rather limited, ranging approximately 10-30 feet. Mice are extremely curious and will explore their territory daily and any new object introduced into their home range. Prolific breeders, house mice will produce offspring year round under ideal conditions. Mice are also color blind and can recognize objects that are 10 feet or closer.