10 Beneficial Plant and Animal Pests

Purdue University offers a definition of “pest,” with which most people would be likely to agree: “A pest can generally be defined as any animal, plant, or other organism whose biology, behavior, or location places it in direct conflict with humans. Because some insects threaten human health, destroy food, damage structures or landscapes, or cause general annoyance or anxiety, they are considered pests.”

Certainly, for a variety of reasons, poison ivy, dandelions, termites, ticks, mosquitoes, maggots, spiders, scorpions, rats, and bats would be described as pests by many. As undesirable, disgusting, or frightening as these pests may be to the majority of us, they’re not simply irritating or dangerous. The 10 plants and animals (yes, insects and arachnids are animals) also provide, each in their own ways, important benefits to us or the world we share with them.

Related: 10 Impressive Examples Of Animal Self-medication

10 Poison Ivy

Almost anyone who’s come into contact with poison ivy knows about the rash and maddening itch it causes. (A lucky few, it seems, are immune to the plant’s toxic effects.) Poison ivy, along with poison oak and poison sumac, contains urushiol, which can trigger an allergic response in sensitive individuals. Upon contact with the skin, urushiol binds to proteins and activates the immune system, prompting the release of histamines. Histamines play a crucial role in the body’s defense against foreign substances, but they can also cause itching, redness, and inflammation. The persistent itching sensation is a result of the body’s attempt to eliminate the perceived threat. Scratching the affected area, however, can worsen the symptoms and potentially spread the urushiol, leading to more extensive irritation.

However, as Susan Pike notes in an online article, poison ivy also has its benefits. White-tailed deer and some birds even eat it. Indelible ink can be made from the plant’s sap—the same “oily sap called urushiol that triggers an allergic reaction [on] contact with skin.” Poison ivy might even be a way to treat sewage since it well withstands being flooded by wastewater.^[1]

9 Dandelions

Like other weeds, the dandelion is considered obnoxious, especially by homeowners and others who put in hours of hard work each weekend to maintain a perfectly manicured lawn. If a single dandelion takes root, the weed is likely to take over the entire yard, flowerbeds included.

As difficult as it may seem to believe, the Cleveland Clinic suggests that dandelions actually are beneficial, both to nutrition and our general health. They’re a great source of vitamins A, C, and K; they provide folate and calcium; and they’re chockful of potassium. They also make a passable wine, according to some palates.

But that’s not all. Their roots, leaves, and flowers are replete with antioxidants that defend our bodies from free radicals. Dandelions “reduce inflammation” and act as “a natural diuretic,” helping to control blood pressure. They could also control Type 2 diabetes and lower both blood sugar levels and cholesterol.

Some even suggest that dandelions be eaten fresh or cooked as greens in a salad, drunk as wine or tea, or roasted in a beverage similar to coffee.^[2]

8 Termites

Termites have an unlikely fan: a pest-control company that sings their praises—all three of them. According to Mike McDonald, writing for Rove Pest Control, although these insects are known universally as pests, they are of great importance to the ecology of forests. Their decomposition of dead trees converts wood back into fertile soil. Termites also aerate the soil, allowing rain to better water vegetation, which has the additional effect of improving soil quality even more.

Finally, in some countries, termites are a nutritious food source. Research shows that the queen provides sodium, and the soldiers supply manganese. Termites are also rich in vitamins A and C and low in fat and anti-nutrient components, but they provide protein and other micro- and macronutrients.^[3]

7 Ticks

Yes, ticks are bloodsuckers, and they can transmit diseases. But they’re not all bad. In fact, as Sarah Cairoli points out, ticks feed on reptiles, amphibians, and birds, as well as a number of woodland animals, turkeys, and some lizards. They also “help control wild animal populations.”

Scientists have found yet another beneficial use for these parasites: Ticks indicate the “overall health and stability” of the ecosystems they inhabit. The more ticks there are, the fewer the number of small animals’ predators; the fewer ticks, the more such predators. As Cairoli says, “Scientists use this information to help prevent animal extinctions and monitor potential environmental problems.”^[4]

6 Mosquitoes

Mosquitoes, seemingly innocuous insects, pose a significant threat to human health by acting as vectors for various diseases. Female mosquitoes, in particular, require blood meals to nourish their eggs, and during this feeding process, they can transmit pathogens from one host to another. Mosquitoes are notorious for spreading diseases such as malaria, dengue fever, Zika virus, West Nile virus, and chikungunya. These illnesses collectively contribute to millions of infections and numerous fatalities worldwide each year.

However, the U.S. National Wildlife Federation wants us to know that this bloodsucking parasite, the mosquito, also benefits us. About half of these insects pollinate flowers (males feed on nectar, females on blood). Indeed, for some wild orchids, mosquitoes are a primary pollinator. Both as adults and larvae, these pests are menu items for dragonflies, turtles, bats, and some birds, hummingbirds included.^[5]

5 Maggots

Even in their infancy, as maggots, flies benefit some folks. These babies, Healthline says, are sometimes fried and eaten; they’re also used to make the Sardinian delicacy known as “casu marzu,” which translates, in English, to “maggot cheese” or “rotten cheese,” a dish prepared specifically as a breeding ground for maggots. As long as the maggots are alive, it’s safe to consume the cheese—or so it’s said.

People who enjoy maggot meals, however, should exercise caution since ingesting the fly larvae can cause myiasis, a condition in which a maggot lives in and parasitizes its host’s mouth, stomach, or intestines, causing serious tissue damage that requires medical attention. Eating maggots (or maggot-infested food) can also cause bacterial poisoning or an allergic reaction.

But maggots also benefit human health by cleaning wounds as they consume dead tissue, reducing inflammation, preventing infections, and reducing complement protein levels. For as long as a month, their secretion, when boiled, also suppresses the immune system, which can facilitate healing.^[6]

4 Spiders

Not all spiders are harmless—far from it, in fact. The bites of some, such as the black widow, the hobo, the six-eyed, the brown recluse, and others, can be painful and even fatal.

Nevertheless, despite their often being designated as pests, spiders control crop-destroying insects, decrease insect-borne diseases, and decrease the number of stings and bites delivered by other predatory pests, including bloodsuckers. In addition, some spiders provide additional health benefits. Spider venom is not only used in developing antivenom for harmful spider bites, but it may also help to reduce pain and could be used to treat strokes and muscular dystrophy as well.

Additionally, the study of spider silk has led to innovations in materials science and biotechnology. Spider silk is known for its remarkable strength and elasticity, and researchers are exploring its use in the development of lightweight, durable materials for medical sutures, artificial ligaments, and even bulletproof clothing. Despite their often misunderstood reputation, spiders offer a fascinating array of benefits across various scientific and practical domains.^[7]

3 Scorpions

Scorpions, arachnids known for their distinctive pincers and venomous tails, pose potential dangers to humans due to their venomous stingers. While the majority of scorpion species are not lethal to humans, some possess venom that can cause severe reactions, particularly in vulnerable populations such as children, the elderly, or individuals with compromised immune systems. The severity of scorpion stings varies, ranging from localized pain and swelling to systemic symptoms like difficulty breathing and muscle twitching.

In regions where medically significant scorpions are prevalent, envenomations can lead to medical emergencies. Though fatalities are rare, prompt medical attention is crucial in managing scorpion stings effectively. Understanding the habitats and behaviors of scorpions, along with adopting preventive measures, can help minimize the risk of encounters and potential harm from these ancient arachnids. But are they always bad?

According to one study, scorpion venom may not only be a medical threat to human health but could also be a “valuable source of bioactive molecules that [lead to] the development of new therapies against current and emerging diseases.”

More specifically, the authors indicate that the insect’s venom can potentially lead to therapeutic use in treating pain, cancer, bacterial infections, fungal infections, viral infections, parasitic disease, inflammation, and immuno-suppressive disorders.^[8]

2 Rats

During the Middle Ages, rats caused the bubonic plague—or so some believe. Actually, the bacterium Yersinia pestis caused the bubonic plague, but this pathogen was transmitted largely by infected fleas that infested rats. The rodents also carry a variety of other pathogens that can cause a number of serious diseases, as do the rodents’ urine and feces.

The benefit of rats lies largely in their many past and present contributions to scientific research. Currently, biomedical research that relies on the use of rats as—well, guinea pigs, so to speak—includes investigations into cancer, obesity, diabetes, cardiovascular disease, immune system disease, and neurological diseases like Parkinson’s, Huntington’s, and Alzheimer’s.

A rat’s physiology is a little closer to humans than that of mice, too, and it is easier to track. Rats are also much more intelligent than mice. Even more remarkably, rats “have easily observed behaviors that correspond, to varying degrees, with human behaviors and experiences, such as compassion, fear, cooperation, care-taking, and various types of pro-social and anti-social behavior.” These human-like behaviors and rats’ clear personalities also add to their value “in a wide range of behavioral, cognitive, learning and neuroscience research.” For these reasons, scientists generally prefer rats over mice as subjects of experimentation and research.^[9]

1 Bats

Bats are known to carry the virus that causes rabies, and according to LiveScience, they also carry 59 other viruses that can be transmitted to humans. Nevertheless, they are important pollinators. The U.S. Department of the Interior states, “Without bats, say goodbye to bananas, avocados, and mangoes” because these fruits depend on bats for their pollination.

Their benefits also include their reduction of the insect population, for which bats have an enormous appetite, consuming their body weight in insects each and every night, thereby helping to protect farmers’ crops.

They are of critical importance to human health, too, since 80 medicines come from plants that rely on bats for their survival. Research on bats has led to developments in vaccines, just as bats’ ability to navigate the nighttime skies using echolocation has “scientists develop navigational aids for the blind.”^[10]