Mice are very prevalent; however, rats are far more prevalent. Rat populations are plentiful in Indiana. They inhabit areas near humans due to the ease-of-accessibility to food and water sources, such as garbage, bird/squirrel feeders, and yard ponds. Rats are omnivorous, eating nearly anything with preference of grain-based foods. Rats can easily enter most homes and businesses by squeezing through tiny structural entry points. Minor rat colonies can quickly escalate to infestation due to their constant breeding, large litters, and early reproduction capabilities. A handful of rats can quickly develop into hundreds within months and approach thousands after a year. Rats are mostly active at night and commonly gnaw through drywall and wood to access food supplies. They can also nest and chew through wiring, ductwork, and insulation in walls and attics. Their feces and urine droppings create contamination that can develop a long list of parasites, pathogens, and diseases. Common species of rats are the brown Norway rat (Rattus norvegicus), and black “roof” rats (Rattus rattus). The difference between rat and mice species can be identified by their size, color, characteristics, and size of droppings.
The brown Norway rat grows up to 20 inches with an equal-sized body and tail. Their fur is course and typically grey or brown in color.
Black rats are similar to Norway rats, but smaller, growing to 5-7 inches and prefer to enter, inhabit, and exit attics and rooftops.
Rat and mice fur is greasy and create traces of smell which can attract additional populations to homes and businesses.