Rodent Myths And Half-Truths

Over the years, many popular magazines and movies have featured stories about rodents. In this age of information technology, good information can be transferred quickly. On the other hand, the Internet & poorly researched articles can serve to quickly misinform the public.

The following are myths, misconceptions, or half-truths commonly heard from people about the rodents in their neighbourhoods.

Rodents love cheese


MYTH: Cheese is a Favourite Mouse Food (& Great Bait)
FACT: This myth is full of holes. A mouse’s typical diet consists of seeds and fruit. Mice don’t really like cheese – although they will eat it if it is their only food. Ideal baits are peanut butter, chocolate, and meats such as bacon.

MYTH: Mice do not have Urine Bladders
FACT: Mice and rats do urinate relatively often compared to some of the larger mammals. But they do have bladders.

MYTH: Cats or Dogs Can Control Mice
FACT: Cats may kill the occasional young or old rodent, but they do not control rodent infestations.

MYTH: Mice Grow to Become Rats
FACT: Although they are closely related, rats and mice are different species.

MYTH: I Only Have One Mouse
FACT: Most likely, there is more than one in your house. Mice reproduce rapidly. Mice will reproduce year-round in stable environments with adequate food, water and shelter. In fact, a single female mouse may produce up to 60 offspring annually.

MYTH: Mice Require Water to Survive
FACT: Water is not essential for the survival of a mouse. Typically, they are able to fill their water needs from the foods they consume – even dry cereal.

MYTH: Mice Travel All Over the House in Search of Food
FACT: Mice will only explore a limited home range – approximately 10m outside of their nests. This is another reason why the key to effective trapping is location, location, location!

MYTH: Mice Consume Bait and Go Outside to Die
FACT: There is no evidence nor has there ever been that rodents would exit buildings seeking water and then die outside, although this would be very convenient. Additionally, a rodent bait has never existed that would prevent decaying odour should they die inside. Most times rodents succumb to death in their own nests.


MYTH: One, Two... Nine... Rats Per Person
FACT: No one knows how many rats per human exist in any city. It probably ranges from zero to several dozen rats per person in any given area. It is only safe to say we know there may be dozens or millions of rats in any one city, depending on many urban environmental factors.

MYTH: Sewers Rats and Wharf Rats are Different
FACT: Norway rats may be called “sewer rats”, wharf rats, river rats, alley rats, house rats and barn rats. Some people mistakenly believe there are different “varieties” of rats according to these names.

MYTH: Rats Must Gnaw or Their Teeth Will Continue To Grow
FACT: Not true. Rats maintain incisor growth end sharpness by grinding the lower incisors against the uppers. They do not need to gnaw on objects, although they will supplement tooth grinding with object gnawing.

MYTH: Rats as Big as Alley Cats
FACT: The Norway rats that inhabit sewers are not necessarily any larger than their cohorts inhabiting an alleyway or park bush above ground. In fact, they could just as easily be smaller. In extensive studies of the sewer rats of London, the heaviest rat captured weighed over 400g. But larger rats have been recorded in and around farms. The heaviest Norway rat ever reported was around double this.

MYTH: Rats Have Become “Immune” to Most Rodenticides
FACT: It is true that many rats and mice are now resistant to the first-generation anticoagulant rodenticides. Luckily, however, so far most rats are still quite vulnerable to the second-generation anticoagulants.

MYTH: Mother Rats Teach Their Babies to Avoid Traps and Poisons
FACT: Young rodents avoid objects and food items simply by following their mother around just after being weaned. If the mother rat bypasses a trap or bait, a young rat may also bypass these items. The mother rat likely passed the baited traps due to more attractive resources further along or because she is fearful of any new objects.

MYTH: Rats are Aggressive and Attack Children and Pets
FACT: Some rats, if provoked and cornered, will fight their way out of the confrontation, as will many wild animals. But most rats do not outwardly attack humans. Young babies, bed-confined elders, and the homeless sleeping in doorways and alleys, however, are occasionally bitten by unprovoked rats. Most likely these individuals fall asleep with food residues on their hands or faces, and foraging rats attempt to lick or chew the food residues off the sleeping individual.

MYTH: Sewers Rats Are Mutated - Blind and Unusually Large
FACT: The Norway rats that infest sewers are neither blind nor unusually large.

MYTH: Construction Causes Rats to Flee Sewers
FACT: Not true. Rats are, for the most part, unperturbed by above ground street construction practices. In fact, they will not leave a suitable sewer system unless their burrows are directly excavated.


MYTH: Moles are Rodents
FACT: Moles are classified as insectivores. The largest part of their diet consists of insects such as grubs, as well as earthworms, spiders, and centipedes.

MYTH: Moles are Blind
FACT: Moles have very tiny eyes that are hidden behind fur. Although moles have extremely poor eye sight, they are not blind. Their eyes allow them to distinguish between light and dark. Moles rely heavily on their sense of smell.

MYTH: Moles Destroy Plants by Feeding on Them
FACT: Typically, landscaping is destroyed by moles due to their tunnelling action in which roots are exposed leading to water loss. In actuality, voles or mice are probably using the mole runways to feed on plants/bulbs.

MYTH: Chewing Gum is Effective Mole Control
FACT: Rumours have persisted that chewing gum and even particular brands can be deposited into the hole to either kill or repel moles. Top scientists in the field give no validity to this theory and do not recommend using chewing gum against moles.

MYTH: Moles are Nocturnal
FACT: Although you may notice fresh mole hills seemingly appearing overnight, in actuality, moles are no more active at night then they are during the day. Simply put, moles tend to be more active during quiet periods. Typically, they tend to be most active during early morning and late night.

MYTH: Moles Live in Communities
FACT: Moles must consume a large amount of food each day and therefore cannot share their tunnel system with others. They live alone. However, it is common that burrow systems of several moles will connect.