Rodents

APPEARANCE & IDENTIFICATION

The largest group of mammals are the true rodents in the order Rodentia – about 2,300 species – so the appearance and identification of rodents is a very broad and diverse topic. However, most rodents that are associated with homes and businesses are mice, rats, squirrels, chipmunks and voles. Other mammals that may be familiar to homeowners, but are not rodents, include rabbits, shrews, moles and groundhogs. Rodents have large incisors they use to chew, have fur, and relatively large eyes.

BEHAVIOR (ACTIVITY)

Rodents are normally nest builders or burrowers, and most rodents choose to build their nests and burrows in places that provide good harborage where they are well protected. Of special importance to home and business owners are the synantrophic rodents, those that like to live with or in close proximity to people. In addition to damaging and destroying human foodstuffs, rodents often will cause damage to items they gnaw upon, a hereditary habit designed to keep their incisor teeth sharp and chiseled down.

Rodents may sometimes bite people or pets if they are startled and must defend themselves, but the most important issue involving rodents is the transmission of rodent diseases to humans and other animals.

WHAT TIME OF YEAR ARE RODENTS MOST ACTIVE?

Rodents are usually active throughout the year inside a structure, but outdoors are less active in the cold weather months than the warm weather months.

DIET

Rodent diets vary a great deal and include plants, seeds, nuts, and vegetables. However, those rodents that are domestic in nature – those that live in close proximity to people – may feed upon almost any food source that people grow, store, package, discard, or otherwise leave lying around.

HABITAT

The principal requirements of rodent habitat are sheltered, protected, infrequently disturbed locations that are also close to food sources and water. Typical rodent habitats around and in buildings are outside under piles of debris, overgrown vegetation, and inside where rooms, closets wall voids, or other such areas that have accumulations of clutter and are near food and water.

HOW DO RODENTS GET IN THE HOUSE OR BUILDING

Rodents usually gain entrance to a home or building through openings that lead inside from the exterior. However, rodents may hitchhike inside when infested items are brought into the building.

SIGNS OF THEIR PRESENCE (COULD BE DAMAGE)

Evidence of rodent activity includes observing the animal, their burrows or dens, plant damage, feces, tracks, rub marks from their oily fur contacting surfaces, damage to inanimate objects caused by gnawing, damage to food and food containers, and bits of paper or vegetation they use to construct nests.

OBSERVATION. Rodents are more active at night; however, if they are seen during the day, that usually means a very large rodent population is nearby.

BURROWS OR NESTS. Holes in the ground around foundations, nests in attics, basements, under kitchen cabinets, or in the basement or garage.

SOUNDS. Rodents produce noise when they move around or build nests.

GNAW MARKS. Rodents spend some of their time chewing and gnawing on wood, plastic, and other hard surfaces in order to keep their teeth chiseled down.

RUB MARKS. As rodents move from one location to another, they may leave body oils from their fur that get deposited onto corners and edges of walls and around holes and gaps they use to enter into a wall void.

DROPPINGS. Rodents excrete a lot of feces, and the presence of fecal droppings is a surefire way to spot an infestation. Remove droppings immediately and wait to see if new droppings appear. NEVER REMOVE RODENT FECES WITHOUT RESPIRATORY PROTECTION.

Rodent footprints and tracks left in dusty locations can also be a sign of an infestation

PREVENTION TIPS

Rodent prevention is dependent on reducing the rodent’s availability and accessibility to food, water and harborage (protection).

  • Remove and keep clean all trash, garbage, and anything else that rodents use for food. Rodents are known to consume just about any kind of refuse that people discard or leave exposed in a home or building.
  • Keep all foods in sealed containers, particularly pet foods.
  • Keep areas dry so there is not a water source for rodents to use.
  • Keep rodents out. For rats, seal any opening that is ½-inch or larger. For mice, seal any opening that is ¼-inch or larger. Seal around doors, windows, attic vents, and holes where plumbing or conduit lines enter the building.
  • Remove anything that gives rodents shelter. Keep vegetation thinned out or removed from the perimeter of buildings and remove any clutter such as debris piles, wood piles, or rock piles that give rodents a place to hide and build their nests.

HOW TO CONTROL

Rodent control generally involves the use of products such as live and kill-type traps, toxic bait products, and traps that employ adhesive substances to capture rodents.

Your pest management professional is the best person to call for assistance in controlling rodents around your property. Some of the products he or she may use include:

  • Both multiple catch and individual catch rodent traps.
  • Liquid and solid bait formulations to help control rodents. One of the more common techniques for bait use is to place the bait formulation in a tamper-proof rodent bait station that helps protect the bait from accidental exposure to non-target animals or people.
  • In situations where rodents are not controlled with conventional products, fumigating transport vehicles or rat ground burrows may sometimes be needed.
  • The use of a community-wide rodent control program may be needed to reduce or rid a large area of rodent pest pressures.