Bat Tick

Need to know

  • These ticks are widespread in Iowa and routinely found in homes and buildings with a bat infestation. 
  • Bat ticks are a type of soft tick, which prefer dry areas and are capable of living for years in the absence of a host to feed on.
  • Bat ticks feed on bats and usually do not leave the bat's presence unless a roost has been abandoned. 
  • Controlling bat ticks requires the elimination of bats from the structure. 

Description of bat ticks 

Image of Carios kelleyi as viewed from above
Carios kelleyi as viewed from above 
  • Family: Argasidae (Soft Ticks)
  • Scientific name: Carios kelleyi
  • Size: variable 1/7th to 3/8th of an inch depending on life stage
  • Color: dark to dirty gray to light black
  • Mouthparts: below the body; not visible when the tick is viewed from above
  • Feeding Behavior: do not engorge; considered to be intermittent feeders taking a blood meal several times a month

One species of soft tick occurs on bats in Iowa. This tick does not have a common name but has the scientific name Carios (formerly Ornithodoros) kelleyi. These ticks are widespread and common in Iowa and are routinely found in houses and buildings that are infested with bats. They hide in cracks and crevices in bat roosting areas and feed on blood from the bats while they are roosting. If bats are present, these ticks usually do not wander far from them. However, if the bats abandon a roost, are removed, or if populations decline for some other reason, the ticks become hungry and start to wander in search of something to feed on. This is when they are usually noticed. 

Life cycle of bat ticks

Bat ticks are a type of soft tick. Soft ticks prefer dry areas and are capable of living for years in the absence of a host to feed on. Few Iowans ever come in contact with soft ticks. Soft ticks do not look like hard ticks, as a consequence, most of us would not recognize them as ticks.

Damage caused by bat ticks 

Image of Carios kelleyi as viewed from below
Carios kelleyi viewed from below 

Bat ticks prefer to feed on bats but will feed on other animals, including humans, if bats are not available. Soft ticks are intermittent feeders taking small amounts of blood every few days. These ticks typically feed (bite) at night. They are reported to have a benign bite. In other words, most soft tick bites go unrecognized since they feed only for a short time and do not cause a reaction in a person being bitten. Soft ticks are not believed to be capable of transmitting the bacteria that cause Lyme disease.

Management of bat ticks  

Controlling bat ticks requires eliminating bats that are present in the home or building. This can only be accomplished by exclusion techniques that seal entrance cracks and holes (also known as "building them out"). There are no pesticides to control bats in attics. The best time to seal bats out of a building is late summer and fall.

In addition to eliminating the bats, it may be necessary to directly control the ticks. This can be done by applying residual insecticides such as those commonly used for cockroaches to cracks and crevices in bat roosting areas and other places where ticks are observed. Spraying without eliminating the bats will probably provide short-term, temporary benefits but will not completely eliminate the bat ticks. Eliminating the bats and waiting for the ticks to starve to death is also not a likely possibility since these ticks have been known to survive months, and even years, without feeding.

Additional resources about bat ticks 

Image of Carios kelleyi next to a dime
Carios kelleyi next to a dime 

Do you live in Iowa and have an insect you would like identified?

The Iowa State University Plant & Insect Diagnostic Clinic will identify your insect, provide information on what it eats, life cycle, and if it is a pest the best ways to manage them.  Please see our website for current forms, fees, and instructions on preserving and mailing insects.   

Contact information for each state's diagnostic laboratory for U.S. residents.  If you live outside of Iowa please do not submit a sample without contacting the Plant & Insect Diagnostic Clinic.  

Last reviewed:
December 2021

Links to this article are strongly encouraged, and this article may be republished without further permission if published as written and if credit is given to the author, Yard and Garden, and Iowa State University Extension and Outreach. If this article is to be used in any other manner, permission from the author is required. This article was originally published on September 12, 2016. The information contained within may not be the most current and accurate depending on when it is accessed.