Bat Bugs/Swallow Bugs

Bat bugs are blood-sucking insect parasites that feed primarily on the blood of bats and Swallows.  Bat bugs are closely related to bed bugs, and are so similar in appearance that they are often mistaken for bed bugs. Microscopic examination is needed to distinguish them. Bat bugs will also bite humans if given the opportunity.

Bird Mites

Bird Mites feed on the blood of common birds including pigeons, starlings, and sparrows. They are semi-transparent in color, which makes them difficult to detect on skin until blood is ingested and then digested; when they may appear reddish to blackish. Bird mites are most active during Spring and early Summer when they tend to wander away from a vacated birds nest. They will then look for an appropriate host and frequently it is a person in the nearest house or apartment.

Raccoon Round Worm

Raccoons are the primary host of this roundworm, which is commonly found in their small intestines. The parasite is most common in raccoons but are also found in mice, squirrels, rabbits, birds, woodchucks, and dogs. Raccoons will shed millions of the microscopic roundworm eggs in their feces. People may encounter the eggs through direct contact with raccoon droppings or by touching a contaminated area or object.  They may later transfer the eggs to their mouths. Small children are particularly vulnerable because they tend to put their hands, and other objects such as bark, wood chips, toys, soil, or even droppings, into their mouths.


Fleas are reddish-brown wingless insects and external parasites with mouthparts adapted for piercing skin and sucking blood. They thrive off the blood of mammals and birds. Their legs are long with strong claws that are designed to grasp a host. A flea can jump vertically up to 7 inches.


Diseases and Viruses


The Hantavirus is very common here in Colorado and is mostly carried by deer mice and pack rats but can also infect other types of rodents. Infection with Hantavirus can progress to Hantavirus Pulmonary Syndrome (HPS), which can be fatal. People become infected through contact with hantavirus-infected rodents or their urine and droppings.


Rabies is a viral disease that causes acute inflammation of the brain in humans and other warm-blooded animals. It is most commonly carried by bats, skunks, and raccoons here in Colorado but can be found in other warm-blooded animals and birds. The virus is usually present in the nerves and saliva of a symptomatic rabid animal. The route of infection is usually, but not always, by a bite. In many cases, the infected animal is exceptionally aggressive, may attack without provocation, and exhibits otherwise uncharacteristic behavior.


Plague is transmitted primarily to humans by the oriental rat flea and is commonly found in rabbits, squirrels, rats, and prairie dogs.  The flea bites an infected animal, and then, feeding on a human, inoculates them with the bacteria that causes the disease.


Histoplasmosis is a disease caused by the fungus Histoplasma capsulatum and is mostly found in soil, often associated with decaying bat guano or bird droppings. Disruption of soil from excavation or construction can release infectious elements that are inhaled and settle into the lung.

Salmonella Food Poisoning

Rodents frequent sewers, rotting garbage, cesspools, and similar sites where Salmonella bacteria thrive.  The bacteria also thrive in the intestinal tracts of rats, mice, and other rodents. If infected rodents travel to stored food, or dishes/silverware, or food preparation surfaces, their droppings can transmit Salmonella food poisoning to humans.

Rat-Bite Fever

Rats and mice bite thousands of people each year and most bites occur in the inner cities of Colorado.  The bacteria that causes the disease is carried in the teeth and gums of many rats and mice.  Although the disease exhibits mild symptoms similar to flu-like symptoms, it can be fatal.  It is of particular risk to infants.  Rat-bite fever can be transmitted by a common house mouse.


Trichinosis results from a nematode that invades the intestines and muscle tissue.  Both people and rats get the disease from eating raw or undercooked pork infected with the nematode.  Rats help spread Trichinosis when hogs eat food or garbage contaminated with infested rat droppings.


Lymphocytic choriomeningitis is a virus infection of house mice that may be transmitted to humans (mainly to children) through contaminated food or dust.