Rodentia is an order of mammals also known as rodents, characterized by a single pair of continuously growing incisors in each of the upper and lower jaws which must be kept short by gnawing. Forty percent of mammal species are rodents, and they are found in vast numbers on all continents other than Antarctica. Common rodents include mice, rats, squirrels, porcupines, beavers, guinea pigs, and hamsters. Rodents have sharp incisors they use to gnaw wood, break into food, and bite predators. Most rodents eat seeds or plants, though some have more varied diets. Some species have historically been pests, eating seeds stored by people and spreading disease.

Black Rats (or their ectoparasites) are able to carry a number of pathogens, of which bubonic plague (via the rat flea), typhus, Weil’s disease, toxoplasmosis and trichinosis are the most well known.

Deer Mouse (genus Peromyscus) is a carrier of emerging diseases such as hantaviruses and lyme disease.

House Mouse (Mus musculus) is a small rodent, a mouse, one of the most numerous species of the genus Mus. As a wild animal the house mouse mainly lives associated with humans, causing damage to crops and stored food.