You’ve probably seen these balls of energy around and thought “is it a rat or a shrew?”. Some of us might easily mistake a shrew for a rat since they both look alike with their mouse-like shape and a penchant for scurrying around at night. However, both very different creatures; for one, we shouldn’t fear the shrew.
Rats are pests, not shrews
Rats are commonly found in areas of human habitation, like in garbage dumps or back alleys where there’s likely scraps of food around. Rats are scavengers and carry diseases that can be passed to us humans by touch, dust inhalation, or flea bites (ie. the plague was brought on by flea bites from infected rats). According to NEA, there are 3 common types of rats in Singapore: the sewer rat, roof rat, and house mouse. The sewer rat is the most common rodent around the world.
Shrews aren’t rodents like rats and mice are. Shrews are usually found in or around green or forested areas, as they are insectivores that feed on insects (ie. cockroaches, crickets) and worms. Singapore is home to the Asian House Shrew, the largest of the shrew species. In fact, you’ll probably hear them first, as they tend to squeak (or twitter) when they detect your presence. While they’re not known vectors of disease, they’re regarded as potential carriers for disease. Shrews actually have venom, and their poison stuns their prey (like mice), but it’s not harmful to humans.
Do both rats and shrews squeak?
Despite what most people think, rats are actually fairly quiet – to our ears. This is because rats communicate with each other through ultrasonic vocalisations which are outside of our ability to hear. They also have a wide range of noises, including hissing.
You’ll hear the shrews squeak – or twitter – loudly before you see them. This is because these beady-eyed critters have super bad eyesight, and they tend to use squeaks as either a way of saying ‘who’s there?’ or as a sort of echo-location (although no hard evidence for that).
Rats and shews feed differently
Both rodents are nocturnal, but when it comes to feeding they eat very differently. A rat has mealtimes: breakfast is after sunset, and dinner is just before sunrise. Also, rats don’t eat a lot in one go – they usually eat 10% of their body weight and hoard the rest.
A shrew eats every single minute it’s awake, so you’ll see this ball of energy hunting frantically – many species of shrew need to it their body weight’s worth of food each day because if they don’t eat within a few hours, they die.
Physical difference between a shrew and a rat
While shrews and rats both have four feet and a pointy head with rounded ears, look closer and you’ll find that they have very different features.
Tail: Rats have hairless, long tails that are almost as long as their bodies. Shrews have a stubbier, shorter tail that’s furry.
Nose: A shrew’s nose is longer than a rat’s – this is because it’s more like a mini snout! Shrews closer cousins to hedgehogs and moles than they are to rats or mice.
Eyes: The shew has tiny, beady eyes, compared to a rat’s which are bigger and bulgier.
Size: The Asian House Shrew is smaller than the Sewer Rat, and when shrews scurry they tend to be lower to the ground than the rats.
Interesting facts about shrews
There are many different types of shrews around the world. They vary widely in size – while the Asian House Shrew (found in Singapore) measures around 15cm, the Etruscan Shrew is a tiny 3.5cm long! In Singapore, there’s another species of shrew: Malayan White-tooth Shrew, which is rare and restricted to the forests of Bukit Timan and Central Catachment Nature Reserve.
When baby shrews need to leave the nest, the mother would lead them out along a caravan line – the young will clamp their jaws tightly to the rear or base of the tail of the shrew in front!
Shrews eat cockroaches, which is one of the most loathed and feared pests in Singapore.