Economic importance of rodent pests: Among rodents, the key pests, mice, and rats damage food and property and spread diseases. Their habit of gnawing objects gives the animal order, Rodentia, its name. In Latin, ‘roder’ means to gnaw. Mice are also the cause of numerous fires by their incessant gnawing of electrical cables. Pest rodents are a serious concern in all countries as their physical attributes, habits, behavior, and adaptability have made them the most successful mammal on earth.
Not all rodents are pests: Among the one thousand seven hundred species of rodents, only one hundred fifty show pest-like behavior, only about twenty are of economic significance. The most common rodent pests are the house mouse, the roof rat, and the sewer rat.
House mouse (Mus musculus): The house mouse, the smallest of the three rodent pests common at homes and businesses, is the most widespread mammal on earth. Its adaptability makes it occur even in farms and natural vegetation. Organized storage is a simple measure to prevent mice infestation as they prefer to nest in dark and secluded spaces. As mice can squeeze through openings one-quarter of an inch, closing such gaps by rodent-proofing material is another measure to curb mice entry. In addition, mice are excellent climbers and can even jump, making them reach uninfested areas quickly.
Roof rats (Rattus rattus): As their name suggests, roof rats live at heights, in the upper parts of buildings, and sometimes nest in trees. Their dark color gives them the name black rat, whereas their ability to swim has led to the other name, ship rat. The roof rat was the vector that spread the fleas, which caused bubonic plagues in history. In addition, roof rats spread other diseases such as typhus, jaundice, and trichinosis. It is a simple roof rat preventive measure to deny them food by securing it in tight containers. As roof rats occur in fruit orchards, removing fallen fruit is a measure that restricts food to them and limits their population.
Sewer rat (Rattus norvegicus): The sewer or Norway rat is a ground dweller that you will find in garbage or debris at night. They make nests at the ground level in basements and other structures to feel secure without disturbance. Unfortunately, like other rodent pests, sewer rats also damage human property by their gnawing, are carriers (or vectors) of disease-carrying ticks, fleas, and mites, and also spread microbial diseases by themselves.
Physical attributes: Though rodents have a keen sense of smell and touch, they have poor eyesight. Though they respond to light, they are color blind. However, they have excellent hearing ability and respond to ultrasonic sounds. Whereas roof rats and house mice are good climbers, the Norway rat does not possess such power. However, all three are good climbers and swimmers; they make their way around, squeezing through openings like their body widths. In addition, the house mouse and the Norway rat jump well.
Neophobia and neophilia: Roof and Norway rats show neophobia or suspicion of new objects. As they do not readily consume poison bait and avoid unknown traps, managing them requires careful planning to overcome such habits. In the case of mice, they are curious creatures that like exploring new objects and, with their neophilia, aid people in feeding them bait or trapping them.
Signs of rodent infestation: Common signs of rodent infestation include their footprints in dust, droppings, urine, hair, gnaw marks, and damage to objects. As rats have a habit of rubbing their bodies against surfaces while moving around, the grease marks from their body oils on surfaces are another sign of rodent presence. Rodent burrows and nests also indicate rodent presence.
Sanitation: Keeping premises clean helps track new rodent activity and discourages rodents who prefer to frequent spaces without any disturbance.
As rats do not prefer open spaces, you can avoid rodent harborage when you have clear two-meter (sixty centimeters) vegetation-free strips along with a building’s exteriors.
Indoor sanitary perimeters inside buildings with bright colors such as white or yellow and are free of storage deters rodents and monitor their presence through droppings or damage.
As vegetation overbuilding walls or roots also provides access to rodents, not allowing plants to grow next to buildings or overhang roofs helps prevent rodents.
Rodent proofing: It is a simple measure to manage rodent pests by creating physical barriers against their access to food or structures is s simple step to managing rodent pests. Denying entry, food, water, and shelter to rodents is easier than controlling rodents that have entered a structure.
Food storage in rodent-proof containers discourages rodents. In addition, fixing leaky traps and condensation prevents moisture access to rodents.
As pet and domestic animal food is also a food attractant, cleaning up for such leftovers helps discourage rodents.
As floor and wall damage allow rodents to enter a building, prompt repairs to a structure minimize rodent entry.
Concrete with glass pieces is good for closing rodent burrows and entryways through floors.
As mice can enter gaps of a quarter inch and rats gain entry through openings of half an inch, sealing such cracks disallows their access.
Metallic rat guards on pipes prevent rodent movement that uses the pipes as runways.
RodeXit proofing strips are good material to seal gaps below doors and overhead doors (shutters). Windows also need rodent proofing by use of metallic screens.