Ticks can bite people and vector disease-causing pathogens, so avoiding bites and controlling tick populations around homes and other buildings are major concerns in tick-infested areas. There are a variety of methods that can be used to reduce tick bites, including the use of various repellents. There are fewer options for area-wide tick control, including eliminating tick habitats, creating mulch or stone tick barriers around lawns, the use of tick tubes to kill ticks on wild mice, and applying acaricides (pesticides that kill ticks) to infested areas. These options can be difficult or expensive to implement, so there is often interest in using animals that are thought to feed on ticks as control. Specifically, there are suggestions, especially on social media, that starting a backyard chicken or guinea fowl flock will reduce the number of ticks and that wild opossums naturally feed on and control ticks.
But are these “common sense” memes true? Will having domestic fowl or opossums in a yard reduce the tick population? There has been a limited amount of research on the topic. The general conclusion is that chickens and guinea fowl feed on ticks but don’t eat enough to decrease tick populations, and opossums likely don’t feed on ticks at all.
Guinea fowl
Three studies have examined whether guinea fowl feed on ticks in North America. Two of these focused on blacklegged ticks (also called deer ticks), while the third focused on lone star ticks. All three studies found that guinea fowl consume adult ticks, and two reported that this feeding reduced the adult tick population. However, two of the studies also examined the impact of guinea fowl foraging on nymphal ticks. Nymphal ticks are smaller than adults, so there is a higher risk of a person being bitten without realizing it and acquiring a tick-borne pathogen. Both studies found that guinea fowl did not reduce the nymphal tick population. Further, the guinea fowl served as hosts for nymphal ticks, which may increase the number of ticks in an area. Because of this, the studies concluded that guinea fowl are not effective at controlling ticks or reducing the potential for acquiring tick-borne pathogens.
Guinea fowl foraging in a lawn-like grassy area. Photograph by Erika Machtinger, Penn State University.
Chickens
There have been no studies on the use of chickens to control ticks in North America. A few studies done in Africa found that free-range chickens kept with cattle will feed on and remove dozens of ticks per bird from the cattle. However, the studies did not quantify the number of ticks on the cattle or demonstrate that this removal was effective at reducing the overall number of ticks present. The species of ticks in Africa were different from those found in North America, and, because these ticks were concentrated on cattle, they were easy for the chickens to find and eat. It is not clear that this research would apply to backyard chicken flocks in North America.
Free-range chickens foraging in fallen leaves. Photograph by RedDrgn056 via Flickr, used under a CC BY-NC-ND 2.0 license.
Opossums
One study examined how “permissive” various mammal hosts are to feeding by blacklegged tick larvae. To do this, they trapped wild animals and experimentally infested them with tick larvae. They found that, in this lab setting, 96.5% of tick larvae were “apparently consumed” and estimated that each opossum must feed on more than 5,000 larval ticks per year and acted as an “ecological trap”. This single study is the origin of the idea that opossums consume so many ticks that they can impact the tick population. However, opossums occur throughout the range of blacklegged ticks, often at high densities in suburban areas. If opossums acted as traps that reduced blacklegged tick populations, then there should be some obvious reduction in tick populations and the incidence of Lyme disease. A more recent study examined the stomach contents of opossums and did not find a single tick in 32 animals that were analyzed. They also summarized nearly two dozen other studies of opossum diet and stomach contents and found that none of those studies reported ticks either. The authors concluded that opossums do not act as “ecological traps” for ticks, and likely do not consume many ticks at all.
Opossums are native animals that are important for the ecosystem, even if they don’t eat a lot of ticks. Photograph by Paul Hurtado via Flickr, used under a CC BY-SA 2.0 license.
Conclusions
Despite what online memes suggest, animals such as guinea fowl, chickens, and opossums do not eat large numbers of ticks, and likely play a limited role in tick control in North America. If you are looking to reduce the number of ticks in your yard, other control methods – such as landscape modifications, using tick tubes, or applying acaricides – are more effective than relying on fowl or opossums.
References and Further Reading
Dreyer, K., Fourie, K. J., & Kok, D. J. (1997). Predation of livestock ticks by chickens as a tick-control method in a resource-poor urban environment. Onderstepoort Journal of Veterinary Research, 64, 273-276.
Duffy, D. C., Downer, R., & Brinkley, C. (1992). The effectiveness of helmeted guineafowl in the control of the deer tick, the vector of Lyme disease. Wilson Bulletin, 104, 342-345.
Hassan, S. M., Dipeolu, O.O., Amoo, A.O., & Odhiambo, T.R. (1991). Predation on livestock ticks by chickens. Veterinary Parasitology, 38, 199-204.
Hassan, S. M., Dipeolu, O.O., & Munyinyi, D.M. (1992). Influence of exposure period and management methods on the effectiveness of chickens as predators of ticks infesting cattle. Veterinary Parasitology, 34(3-4), 301-309.
Hennessy, C. & Hild, K. (2021). Are Virginia opossums really ecological traps for ticks? Ground truthing laboratory observations. Ticks and Tick-borne Diseases, 12(5), 101780.
Keesing, F., Brunner, J., Duerr, S., Killilea, M., LoGiudice, K., Schmidt, K., Vuong, H., & Ostfeld, R.S. (2009). Hosts as ecological traps for the vector of Lyme disease. Proceedings of the Royal Society B, 276, 3911-3919.
Ostfeld, R.S., Price, A., Hornbostel, V.L., Benjamin, M.A., & Keesing, F. (2006). Controlling ticks and tick-borne zoonoses with biological and chemical agents. BioScience, 56(5), 383-394.
Price, A. K., Fritz, R.S., & Ostfeld, R.S. (2004). The use of biological controls for vector-borne diseases: the case of guinea fowl and Lyme disease. Undergraduate Ecology Research Reports. Millbrook (NY): Institute of Ecosystem Studies.
Stafford, K.C. (2007). Tick management handbook. The Connecticut Agricultural Experiment Station Bulletin, 1010, 1-78.
Tsao, J.I., Hamer, S.A., Han, S., Sidge, J.L., & Hickling, G.J. (2021). The contribution of wildlife hosts to the rise of ticks and tick-borne diseases in North America. Journal of Medical Entomology, 58(4), 1565-1587. doi: 10.1093/jme/tjab047
White, A. L., Cumbie, A., Brinkerhoff, R.J., Hynes, W.L., & Gaff, H.D. (2024). Release the hens: a study on the complexities of guinea fowl as tick control. Journal of Medical Entomology, 61(2), 410-417.
