Rats

Tell Me About Rats

The Norway rat is large and heavy bodied with a long sparsely haired scaly tail. The upper parts are usually brown to brownish black and the underparts are paler. Some can have a high degree of spotting or splotching with white. The fur is somewhat course and the ears are conspicuous and covered with spotted hairs. Norway rats are omnivorous, eating practically any organic matter.

Problems

Rats damage human food more through contamination with their urine and feces than by consumption, and can cause structural damage and disfigurement in many ways. Burrowing is potentially damaging, although usually the problem is more cosmetic than structural because burrow systems are instinctively built to remain stable and to not allow water to enter. Gnawing can be a dangerous problem when electrical wires are attacked. Rats can and do gnaw through materials as dense as lead pipe, meaning that most woods are not impediments to them at all.

Solutions

Exclusion

Rats can access buildings through holes as little as 1 inch wide – about the size of a quarter. All such holes and opening should be sealed with heavy-weight material (1/4-inch hardware cloth or heavy-gauge screening is recommended). Heating vents are often overlooked as points of entry, and they should be checked to ensure that access through them by rats is not possible.

Anywhere electrical conduits, utility or air conditioning lines enter a building, the hole that has been made needs to be checked for gaps that will allow entry. Wire mesh can be used to plug openings in walls and floors through which rats might gain entry. Aluminum window screen can be wadded and stuffed into openings to deter rat entry. Caulking or foam sealants can be used to seal openings also, but because rats can gnaw through them, they are best when combined with screening or wire mesh.

Habitat Modification

Proper sanitary techniques constitute the most economic and effective method to limiting rat presence. Mow grass and clear debris close to buildings to reveal burrows as well as openings that rats might use to get inside. Store food in rat-proof containers. Remember that birdseed, grass, and other potential foods are stored in garages and buildings frequently attract these animals.

Store and dispose of garbage properly so that rats cannot gain access. Do not leave pet food outside. If pets are fed outside, leave the food out for twenty minutes and then remove it. Remove old wood or debris piles if rats are a problem – these are frequent havens for these animals.

Long Term Solutions

Where rat infestation has been and continues to be a problem around buildings, the long-term solution to preventing burrowing along foundations can be addressed by creating an L-shaped footer of either hardware cloth or concrete. Bury the footer about 12 inches and extend it from the foundation about another 12 inches. Although rats may begin to dig at the foundation, they will encounter this obstacle, dig down and get frustrated, and then give up.