Positive Impacts

Rats cause direct economic loss by eating grain, polluting food stores with urine and droppings, and chewing wires, pipes, and walls. Economic losses in the U.S. are estimated to be more than $1,000,000,000 per year from this species.

Rats carry and transmit many diseases that infect humans, including typhus, trichinosis, and bubonic plague. Through their association with human diseases, Norway Rats have caused more human deaths than all the wars in history.

Bubonic plague was introduced to San Francisco, California, and has spread to native rodent species, including prairie dogs and pocket gophers. Plague infects U.S. citizens at a rate of 10-15 per year. Learn more.