How Did I Get a Flea Infestation? Causes and Prevention

Ah, spring. It’s a wonderful time of year filled with blooming flowers, longer days, and blood-sucking demon bugs the size of a sesame seed. Yup, it’s the start of flea and tick season — and personally, I am already over this boogeyman-bug horror show. Thankfully, there are more options than ever for combating these blood-thirsty pests and keeping both your pets and your human family safe.

“ Tick control is important not just to take care of pets, but also to prevent establishing a transmission cycle where the pathogens can be transmitted to the humans in the household,” Dr. Maria Esteve-Gasent, an assistant professor at Texas A&M College of Veterinary Medicine & Biomedical Sciences, says.

Navigating life
with a new pet? Head to littleKin!

littleKin™ is Kinship’s home just for puppy and kitten parents. Bop over to check out expert advice, new pet tools, and special deals—all curated for your newest family member.

Get Free Advice

A flea infestation can happen in what seems like the blink of an eye — and it’s up to you to eradicate these pests from your yard, your home, and your pet, and make sure they stay out. Read on to learn all about the causes of flea infestations and what you can do to prevent them. 

Main takeaways

• Because of their extremely rapid reproduction, a single flea can quickly lead to an infestation. 

• Fleas are just 1/8 inch long, making them difficult to spot.

• Fleas can hitch a ride into your home on your pet and even on your clothing.

• Itching is the most common symptom of a flea infestation, but more serious reactions are possible.

• Flea and tick preventatives can help keep your pet safe from fleas.

Related article

How to Identify Fleas on Dogs and Humans

No one wants to find them, but here’s what to look out for.

Will one flea cause an infestation?

It’s happened to many pet parents — you’re casually petting your dog or cat, and you spot a tiny speck in their fur or on their skin. You hope it’s dirt, something picked up somewhere in the yard or house. But no, it’s a flea. And where there’s one flea, you’re likely to find more. Many more. 

A single flea may not seem like a big deal. After all, these minuscule pests are incredibly common and easy to pick up anywhere outside. Can a few fleas cause an infestation? 

Fleas breed rapidly, and if you don’t quickly take action to eliminate the insects from your home and pet, you could quickly find yourself dealing with a full-blown infestation. And eliminating fleas goes beyond a simple treatment for your pet. If you notice a single flea, you need to treat your home and yard as well. 

Can you see fleas with the naked eye?

Fleas are not easy to see, especially on a pet, where their brown or black color often blends in with fur. At just 1/8 of an inch long, an adult flea is hard to spot with the naked eye, and flea eggs, which are about the size of a single crystal of salt, are even harder to glimpse. Instead, you’re most likely to find small black or brown specks on or around your pet’s bedding. These spots are known as “flea dirt” and often resemble coffee grounds, but are actually (sorry) flea feces.

What causes a flea infestation?

A single flea quickly lays eggs in your pet’s fur, which can then fall off and end up anywhere your pet hangs out — on that fluffy pet bed, your sofa, and, yes, your bed if your pet sleeps with you. Most fleas live for only a few weeks, but fleas on a dog or cat can survive for 30 to 40 days. 

Even if your dog rarely spends time outdoors, they aren’t safe from fleas. These tiny insects can jump as high as a foot (a huge distance for their size), making it easy for them to move from their spot in the grass to a host. Look out for signs of fleas in the house, such as black or brown spots on areas where your pet spends time (flea dirt) and tiny black or brown bugs on your pet’s fur. 

Fleas are common pests and difficult to see, making it hard to stop an infestation before it starts. All it takes is a single flea laying eggs in your pet’s fur to create a frustrating situation that requires treating your pet, home, and yard to eliminate the insects.

How to tell how bad a flea infestation is

The most obvious sign of a flea infestation is your pet scratching more than usual. You may also see an irritated patch of skin on your pet, sometimes called a “ hot spot,” that can result from flea bite dermatitis. You may also find flea dirt or eggs in other places around your home, such as on your dog’s bedding or on the furniture. If your dog sleeps on your bed, look out for fleas and flea eggs on bed sheets.

In minor cases, you’ll notice a flea infestation primarily on your pet. Your dog or cat may be scratching excessively, and their skin will likely be irritated. Your pet may also be restless because the constant itching can lead to discomfort. 

In serious cases, fleas can transmit disease to both your pet and humans in the home, including typhus. Fleas can also transmit tapeworms to your pet, which can lead to digestive problems and even weight loss. Some people and animals also have allergic reactions to flea bites, resulting in more intense itching. 

Related article

How to Get Rid of Fleas — Proven Home Remedies

You can stop your home from becoming a literal flea circus.

How to prevent flea infestations

Keeping your home and yard clean can help eliminate the presence of fleas. Make sure to mow regularly to remove places where fleas may reproduce and hide. And simply sweeping and vacuuming your home frequently can reduce the number of flea larvae in your home by 30 percent and eliminate as much as 60 percent of flea eggs. You should also regularly wash bedding and any other fabric products that can be washed.

The best thing you can do to prevent a flea infestation is to regularly give your pet flea and tick preventatives. Even better, more products are coming to the market that utilize natural methods to stave off fleas and ticks; these chews, sprays, and treatments can give you some peace of mind about keeping your pup safe from both bugs and harsh chemicals. Ahead, discover our choices for the best flea and tick preventatives for dogs to keep your whole family safe during the warmer months.

Btw, our editors (and their pets) picked out these products. They’re always in stock at the time we publish, but there’s a chance they’ll sell out. If you do buy through our links, we may earn a commission. (We’ve got a lot of toys to buy over here, you know?)

Best oral chew

NexGard Chew

$30

In the last 10 years or so, the pet market has seen a huge surge of oral prescriptions for flea and tick prevention. At the head of the pack is Nexgard, which works against black-legged ticks, American dog ticks, lone star ticks, and brown dog ticks — all of which are the most common ticks found in the continental United States. Each prescription, flavored chewable is effective for one month and is available in dosages for dogs between four and 121 pounds.

$30 at Chewy

Best oral chew for large dogs

Simparica Trio Chewable Tablet

$195

For added protection, consider Simparica Trio, which also works against black-legged ticks, American dog ticks, lone star ticks, and brown dog ticks — in addition to fleas and heartworm. Released in 2016, Simparica is newer to the flea and tick game than NexGard, but has proven to be just as safe and effective. Simparica also comes in a flavored chewable and is also prescription only. However, Simparica has the added bonus of having a larger weight range than NexGard, with doses available for dogs between 2.8 pounds and 132 pounds.

$195 at Chewy

Best topical spot treatment

K9 Advantix II Flea & Tick Spot Treatment

$80

When it comes to flea and tick prevention, topicals hold one key advantage over oral medication: “Tablets don’t work so much as a repellent, so the tick will still get on your pet, but the tablet will kill the tick fairly well once it bites,” says Dr. Elizabeth Shines, an associate vet at Banfield Pet Hospital in Portland, Oregon. “Topicals tend to work more as repellents and then if the tick does bite your pet, it will still kill the tick.”

So, if you’re looking for more of a repellent or your dog doesn’t respond well to oral flea and tick medication, consider this topical option by K9 Advantix. Available online and over the counter, K9 Advantix is applied between your dog’s shoulder blades and should not come into contact with water for at least 24 hours. This topical also works to kill fleas and ticks on contact, so neither bug has to bite your dog before dying. Available in monthly doses for dogs four pounds and up, K9 Advantix also claims to repel mosquitos. Remember that iconic commercial from the early aughts?

$80 at Amazon

Best all-natural

Kin+kind

$27

Simply put, kin+kind makes natural, sustainable pet products that actually work. With a focus on supplements and topicals, kin+kind’s products address specific issues like hot spots, nose dryness, and allergies. Kin+kind also makes household products for pet-related issues like stain and odor control — all made with natural ingredients. 

• LGBTQ+ Owned
• Sustainable

$27 at Kin+kind

Best spray

Wondercide Flea, Tick and Mosquito Spray

$110

Unless you live in a high risk area for fleas and ticks or have an outdoor cat, a natural product may be the way to go. Wondercide’s lemongrass-scented flea, tick, and mosquito spray is the ideal natural alternative to treat and prevent pests for cats, dogs, and in the home. Give your cat a spritz before they head on their merry way to nibble on your hydrangeas or use it as a quick fix for a pet suffering from fleas. However, if you have an adventure cat, foster pets, or a dog that you take hiking through tick-infested woods before they plop down on the bed both humans and animals sleep in, it’s best to use the heavy duty stuff.

• Women Owned

$110 at Amazon

Even so, these products are the first line of defense in keeping you and your pet safe from a (blood) sucky springtime.

When to consult a vet or pest control expert

In most cases, a flea infestation can be controlled and eliminated without consulting a vet. However, if you notice your pet has other symptoms beyond scratching, such as lethargy or pale gums, don’t hesitate to take them to the vet. Similarly, if you struggle to get rid of fleas in your yard or home, reach out to a professional pest control company. Just make sure that any products they use are safe for your pet. 

References

• “Control Fleas on Your Pet, in Your House, and in Your Yard | Mississippi State University Extension Service.” Msstate.edu, 2020, extension.msstate.edu/publications/publications/control-fleas-your-pet-your-house-and-your-yard. 

• “Controlling Fleas - Texas A&M AgriLife Extension Service.” Texas A&M AgriLife Extension Service, 17 Nov. 2024, agrilifeextension.tamu.edu/asset-external/controlling-fleas. 

• “Fleas.” Illinois Department of Public Health. dph.illinois.gov/topics-services/environmental-health-protection/structural-pest-control/fleas.html. Accessed 25 Nov. 2024.

• “Fleas: Inspection, Treatment, & Prevention.” Dunn County Health Department. dunncountywi.gov/vertical/Sites/%7B97C2FC1A-69D7-4F5C-BA23-79B5C833BED5%7D/uploads/Flea_handout.pdf. Accessed 25 Nov. 2024.

• “How Do Fleas Develop?” Michigan State University - College of Agriculture & Natural Resources, May 2007, www.canr.msu.edu/ipm/uploads/files/fleas.pdf. 

• Los Angeles County Department of Public Health. “Occupational Health: Flea Prevention.” Frequently Asked Questions (FAQs), CDCP-ACDC-135-01, 5 Oct. 2018, www.publichealth.lacounty.gov/hea/library/topics/typhis/CDCP-ACDC-135-01.pdf. 

• Peres, Gabriel, et al. “Breakfast, Lunch, and Dinner Sign: A Hallmark of Flea and Bedbug Bites.” Anais Brasileiros De Dermatologia, vol. 93, no. 5, Aug. 2018, pp. 759-60. https://doi.org/10.1590/abd1806-4841.20187384.

• “Preventing Fleas.” Fleas, 4 June 2024, www.cdc.gov/fleas/prevention/index.html.

• Rust, M.K. “How to Manage Pests.” Fleas Management Guidelines–UC IPM, Sept. 2010, ipm.ucanr.edu/PMG/PESTNOTES/pn7419.html. 

• Tomberlin, Jeffery K., and Kimberly Schofield. Fleas Among Us. Texas Cooperative Extension, www.maine.gov/dacf/php/integrated_pest_management/school-ipm-curricula/elementary/documents/TeacherManual.pdf. Accessed 25 Nov. 2024.

• University of California. “Fleas.” Pest Notes, Sept. 2010, ipm.ucanr.edu/legacy_assets/PDF/PESTNOTES/pnfleas.pdf. 

• University of California Statewide IPM Program, et al. INTEGRATED PEST MANAGEMENT: FLEAS. 2016, cchp.ucsf.edu/sites/g/files/tkssra181/f/Fleas_FCCH_IPM.pdf.