Rodent Information and Control

Mice and rats are known as commensal animals because unlike other wildlife who prefer to avoid contact with people these rodent species will readily live in close contact with humans especially when their nests are disturbed due to construction, severe weather, or the close proximity of food and water.


- Rodents cause damage by gnawing and can chew through soft concrete, dry wall, PVC pipes, and electrical wiring. It is estimated that 20% of all fires of unknown origin are caused by rodents.


- A number of diseases can be transmitted by rodents or their parasites such as:

Murine Typhus
Description: Fever, headache, rash, nausea, and body aches
Carrier: Rats, Mice
Mode of Transmission: Rat flea bite
Comments: Rats and their fleas can be the natural reservoir for the rickettsial organism that causes the disease. Most cases occur in South Texas, but there have been cases throughout the state

Hanta Virus
Description: Flu-like symptoms, renal failure, severe respiratory distress
Carrier: Various rodents; primarily deer mice
Mode of Transmission: In feces, urine, body fluids
Comments: The virus can be present in mouse dropping and can be inhaled when airborne. HV outbreak in 1994 resulted in more than 50 death in 17 states. At least 7 different strains of HV have been identified

Salmonella (Food Poisoning)

Description: Causes intestinal disorders
Carrier: Rats, Mice Mode of Transmission: Rodent feces contamination
Comments: The World Health Organization estimates that 20% of the world's food supply is destroyed or contaminated every year by rodents

Rat-Bite Fever
Description: Relapsing fever that may last several months
Carrier: Rats, Mice
Mode of Transmission: Bacteria in mouth and nose of rodent, transmitted via bite, scratch, or contaminated food
Comments: Occurs worldwide, but is most common in Asia

If you are seeing rats near your property, call the Environmental Health Division at 972.919.2536. Although rodent bait boxes cannot be placed on private owned property, enclosed rodent bait boxes can be placed in common areas and City owned property such as alleyways or greenbelts to aid in the control of rodents before they can enter your yard or home. If rodents have accessed your home or property it is recommended that you call a licensed pest control company for elimination.

To avoid attracting rodents into your yard:
  • Keep your property maintained to avoid providing shelter for rats and mice
  • Remove all pet food, bird seed, and water bowls from your yard at night when rodents are active
  • Maintain waste receptacles with tight fitting lids
  • Repair or seal all holes in the interior and exterior of your home, and gaps or openings around pipes and conduits
Take a look at our newsletter to learn more about rodent control

The following fact sheets by Bell Laboratories are excellent resources with information on rats and mice: