Rats are vectors as they can transmit diseases to humans and animals. Rat-transmitted diseases, such as leptospirosis, hantavirus and murine typhus, can be passed to humans through direct contact or breathing in dust contaminated with rat urine or droppings, or via a flea bite from an infected rat. These diseases can be minimised by keeping the rat population low. All stakeholders, including land owners, building managements, food shop operators and supermarket operators, must therefore remove food sources and areas of harbourage by putting in place a good system of housekeeping, refuse management and routine pest control checks and treatment. Members of the public can also do their part to ensure that the environment around them is clean by ensuring that their litter and food waste are properly disposed into bins and rubbish chutes to eliminate food sources for rats.

There are three common types of rat species in Singapore, namely, the Rattus norvegicus (Sewer Rat), Rattus rattus species (Roof Rat) and Mus musculus (House Mouse). Though similar in appearance, their features vary slightly (see table below). Generally, these three species are able to produce four to 12 pups per litter and have an average lifespan of one year. The Suncus murinus, or the Asian House Shrew, is an insectivore and often mistaken as a rat. It can generally be differentiated from a rat by its pointed snout, its shorter thicker tail, and smaller eyes. Like the rat,the Asian House Shrew is a nocturnal animal with similar reproductive prowess and can be found in Singapore's urban areas near homes and areas with human activity, such as vegetated areas and gardens.

Shrews are often mistaken as rats in our urban setting but they are a different species from rats. They are usually found in or near gardens foraging for seeds, insects (such as cockroaches and crickets), and worms in leaf litter and dense vegetation. Though shrews have not been implicated as vectors that transmit diseases, there have been reports of shrews found harbouring pathogens such as hantaviruses and leptospira bacteria. They should thus be regarded as potential carriers of diseases, and handled with care, much like other wild animals. Although there is no need for specific measures to control the shrew population, our rat control measures will likely have a secondary effect in keeping the shrew population in check. 

	Rattus norvegicus (Sewer Rat)	Rattus rattus species (Roof Rat)
Features
Fur	Doraum grey-greyish brown	Doraum brown-dark brown
Head	Blunt muzzle	Pointed muzzle
Tail	Dark above and pale below, scaly	Uniformly dark with fine scales

	Mus musculus (House Mouse)	Suncus Murinus (Asian House Shrew)
Features
Fur	Doraum greyish brown to brown	Glossy black or dark brown
Head	Pointed snout Small rounded ears	Small eyes Long pointy snout Conical sharp teeth Long jaws containing rows of pointed teeth
Tail	Uniformly dark and sparse hair	Thick at the base and hairy