Ticks have been terrorizing cottagers in the more southerly parts of Canada for years—but what terrorizes ticks? Population numbers of blacklegged ticks (also known as deer ticks) are on the rise, and not just in cottage country, so we wondered what animals might be good at controlling ticks. The ever-growing presence of ticks in suburban and urban areas poses an increased risk of Lyme disease for humans and animals without even leaving the sidewalk. We know that ticks like to feed on people, but it also turns out that the pesky arachnids have many natural predators of their own. So, how does each one hold up when tested on their ability to control the blacklegged tick population and reduce the spread of Lyme disease?
If “Reducing the Tick Population 101” were a class, spiders would be failing. While spiders do in fact eat ticks, there is no method to their snacking madness; it seems they will eat just about any creepy crawly that presents itself, meaning they are not very useful for targeted tick control. Spiders just don’t eat enough blacklegged ticks to affect their population, and therefore don’t do much to mitigate the spread of Lyme disease. However, there are some other things spiders are pretty good at, so we’ll forgive them for their lack of effort on the tick front.
Amphibians: frogs, toads, and lizards—Grade: F
Frogs, toads, and lizards are right down at the bottom of the class alongside spiders. Though these amphibians have been known to eat ticks as part of their regular insect diet, there is not much evidence to suggest that ticks are a preferred delicacy. Rather, similarly to spiders, their appetite for ticks is occasional, when opportunity strikes. We can appreciate their stellar hunting abilities and the small amount of ticks that they do consume, but they still receive a failing grade.
Chickens and wild turkeys—Grade: D
These birds are just scraping by when it comes to their tick-control capabilities. Chickens and wild turkeys eat ticks as part of their regular grazing diet, but are also prone to attracting ticks that are looking to feed on them. Because the birds don’t groom themselves as well as, say, an opossum, their self-care won’t do much to actually reduce tick populations. While some studies have found that chickens can be somewhat effective at controlling ticks, these studies have involved different kinds of ticks, such as the Asian longhorned tick, rather than blacklegged ticks, so not much can be said of their impact on the spread of Lyme disease.
Guinea fowl—Grade: C+
Guinea fowl may not get top marks on the tick-control front, but they’re definitely passing the class. Though they are native to Africa, guinea fowl have been introduced as a tick-control method in areas of North America including Nova Scotia, with many people keeping the birds in their yards for this purpose. Guineas eat ticks and other insects without destroying vegetable or flower gardens, which is a plus. However, similarly to chickens, they don’t consume enough ticks to significantly impact population growth, and often become targets of ticks themselves. Also, their ear-piercing cries can be off-putting to many people. Ask yourself: is slightly controlling ticks really worth sacrificing your—and your neighbours’—ear drums?
It turns out that grey squirrels like more than just nuts. In a study done by the Cary Institute of Ecosystem Studies, it was found that, in addition to those they consume during regular eating activity, grey squirrels eat many of the unlucky blacklegged ticks that try to feed on them (though, spoiler, not as many as opossums do). However, ticks are usually much more successful at feeding to completion on a squirrel than on an opossum, meaning that the ticks have a chance to finish feeding and go onto another life stage. So, though squirrels can somewhat mitigate the number of blacklegged ticks in their environment, they still come second in the class.
Coming in at top of the class, opossums are the unsung heroes of blacklegged tick control. When studied alongside other common mammals by the Cary Institute, opossums were found to consume up to 96.5% of the larval-stage ticks that tried to feed on them. Given this data, opossums certainly seem to be doing their part in controlling the tick population—it is estimated that they can eat up to 4,000 ticks per week. The Virginia opossum is the only marsupial found in Canada, and can be found in the southern regions of Ontario, Québec, and British Columbia. Though they are often thought of as a nuisance, it might be time to rethink your stance on opossums, especially next time you escape an outdoor hike without a tick to show for it.
Nematodes—Grade: I (Incomplete)
According to studies done in the United States, these parasitic roundworms certainly show promise in the realm of blacklegged-tick control—we would have given them an A, but we couldn’t find evidence that they are regularly used in Canada for this purpose just yet, so we had to give them incomplete marks. In Canada, you can find native beneficial nematode species that are effective against pests such as lawn grubs, weevils, and Japanese beetles. These nematodes can be introduced into the environment as a form of natural, non-toxic pest control—and the best part? As long as they are a native species of nematode, they are completely harmless to humans, animals, pollinators, and beneficial garden insects. Application is as easy as mixing them with water, spraying the areas you want to protect, and letting them do their thing. In the U.S., you can buy nematodes that specifically target adult female ticks, disrupting the reproductive cycle and effectively limiting the amount of ticks that are being born; these beneficial nematodes are from the genera Steinernema and Heterorhabditis. Part of the appeal of nematodes for tick control is that they are easier to introduce into your environment than, say, an opossum that you keep in the backyard (although, to each their own).
Though these animals certainly do their part in controlling the tick population, ticks are increasingly part of the natural environment, and the best way to protect yourself is through prevention. The most important thing to remember is that ticks are never going to go away completely (no matter how many opossums may wander through your neighbourhood). Make sure to perform regular tick checks—on both yourself and your pets—after coming in from spending time outdoors.