How To Identify Fleas – 5 Ways To Spot These Pests

Infographic of man sitting on his couch with fleas

If you’re a pet owner, chances are that you’ve spotted a flea on your fur baby at one time or another. These pesky little insects are not only irritating for your four-legged friends but can also seriously affect their health in some cases. 

And if you’re not vigilant about treating and preventing fleas, you could end up with an infestation in your home. Even if you’ve only spotted a few fleas on your pet, it’s wise to inspect your home for other signs of their presence. 

Female fleas can lay up to 50 eggs in a day, which is definitely the kind of population explosion you want to prevent. 

In this article, we’ll go over how to identify fleas on your pet and in your house and also cover ways to get rid of them. But first, let’s get a little bit more familiar with pet enemy number one. 

What Fleas Look Like 

A huge part of flea control is knowing what they look like. Fleas are dark brown to black in color, but take on a reddish brown tone after feeding on their host’s blood. These flat, wingless insects have six legs and biting mouthparts. And even though they usually only measure about ⅛ of an inch (1.5 to 3mm), their powerful hind legs can propel them up to 12 inches. Yikes! 

When seen from above, fleas have a very thin profile in contrast to other external parasites like bed bugs or ticks. Here’s a quick video to help you tell the difference.

What Fleas Eat 

Fleas are hematophagic, which means they dine on blood more than any other food source. In fact, fleas actually need a blood meal to reproduce and can drink up to 15 times their body weight. 

Fleas will consume blood from cats, dogs, humans and other animals. But even though it’s their primary food source, they also eat decomposed plant matter, human skin flakes and animal and human waste. 

How Fleas Reproduce 

There are four different stages to the flea life cycle. It’s important to recognize all four stages, as adult fleas are only the tip of the iceberg when it comes to flea infestations. 

Egg Stage: 

Fleas start their life as small, white oval eggs. Although eggs are visible to the human eye, many pet owners confuse flea eggs with dandruff. Eggs can be laid on your pet’s fur, soon falling off into the surroundings. Flea eggs can end up in pet beds, carpets and furniture. 

Larvae Stage: 

After only a few days, these eggs hatch into very tiny worms with reddish-brown heads. 

The Pupa Stage: 

After about 3 or 4 weeks, larvae wrap themselves in a cocoon called a pupa. These pupae are initially yellow in color but eventually turn blackish-brown. These cocoons protect the flea from threats in the environment (like insecticides) until they’re ready to emerge. 

The length of time that a flea spends in the cocoon will vary depending on the conditions. In fact, fleas won’t emerge from their pupae until they sense the presence of a blood host. 

Adult Fleas: 

Fleas emerge from their cocoon as adults. Amazingly, female fleas begin to feed on their blood host in just a few hours and will mate and begin to lay eggs soon after.

The Most Common Types of Fleas 

Although there are various types of fleas (including dog fleas, sand fleas, human fleas and rat fleas), one of the most common types is the cat flea. And don’t let the name fool you—these little critters are happy to take up residence on your dog and will also dine on your blood if given a chance. 

The dog flea, surprisingly, is not nearly as prevalent as the cat flea. 

How Fleas Can Affect Your Pet 

Woman in her bed trying to figure out how to identify fleas

Fleas are more than a minor nuisance to your pets. Here are some of the most common effects these pests cause for your furry friends.

Itchy Bites 

As we all know, the itching caused by fleas is very irritating to your pet. Not only can the initial bite be unpleasant, but the saliva can make your pet itch as well. Flea saliva is an allergen and contains anticoagulants to soften skin so that sucking and biting are easier. 

When your pet scratches and chews on these bites, they can end up with contact dermatitis (red itchy welts). And if the skin of your pet is actually broken, it could lead the way to a secondary bacterial infection. 


Fleas often carry tapeworm eggs which can enter your pet’s digestive system. Although a tapeworm infection usually won’t cause major harm to your pet, it can lead to more serious problems for puppies or older dogs. 


Fleas feed mainly on blood. If your pet is overrun with fleas, it can actually lead to anemia. This can be especially dangerous for smaller breeds, cats or kittens and geriatric pets. 


Although not as common as other problems caused by fleas, a bacteria they carry called Bartonella can infect pets in some instances and lead to vomiting, coughing, diarrhea and other problems. 

This disease can also be spread to humans if an infected pet bites you. Though not very prevalent, it’s always good to be aware and try to keep your pet free of fleas.

Where Fleas Live 

Outside your home, fleas tend to live in grassy and wooded areas and like high humidity. Although fleas can be a nuisance year-round, they especially thrive in the warmer months. 

When pets are outside, they can pick up one of the hitchhikers and bring them into your home. But they can also enter your living space if they jump onto your clothing. In other words, you don’t have to have a pet in order to end up with a flea infestation in your house. 

How to Spot Fleas on Your Pet 

Think your pet might have fleas? Here are some telltale signs.

Itchy and Biting 

These are the most common signs that your pet may have fleas. If your pet is itching and biting, check their fur to see if you can spot any adult fleas. 

On cats, fleas tend to migrate toward the furry head and neck area. On dogs, fleas are commonly found on the hindquarters. They also like to hang out in nooks and crannies like the armpit and groin area. 

Fur Loss and Dermatitis 

Red areas on their skin and a loss of fur are other signs that your dog may have a serious flea problem. 

Flea Dirt (Black, Pepper-like Flakes) 

Flea dirt is actually flea feces and looks like black, pepper-like flakes that may show up on your dog. You can use a flea comb to spot it. If you want to confirm that it’s flea feces, just run a wet paper towel over it. 

Because flea feces is composed mostly of digested blood, it will turn red when it’s wet. 

Pale Gums 

If your pet has a serious flea problem, it could lead to anemia which turns their gums a paler shade due to a lack of red blood cells. 

How to Spot Signs of Fleas in Your Home 

Unfortunately, spotting adult fleas on your dog may be just the tip of the iceberg. In order to detect if your home is infested, it’s important to spot the signs that these insects have taken up residence in your house. 

Flea Dirt 

Flea dirt or feces may also fall off of your pet and end up in other places in your house. You can also look for these black, pepper-like flakes on pet beds, furniture, your carpet or your own bed.

Flea Eggs 

Flea eggs are tiny, white ovals that may fall off of your pet’s body into other areas. Of course, because of their size and color, they can be difficult to spot. To check for flea eggs, it’s best to use a magnifying glass and check areas that your pet frequents, like their bed, carpets, furniture and bedding. 

Check Your Hardwood Floor 

Unfortunately, having hardwood floors doesn’t make your home immune to flea infestations, as they will also take up residence in the cracks between floorboards. Be sure to check these areas for flea eggs and flea dirt with the aid of a magnifying glass. 

Do The White Sock Test 

Another test you can do to check for fleas is to put on a pair of white knee socks and wear them around the house for a few hours. If you have an infestation, chances are a few adult fleas will end up on your socks. 

Check Yourself for Flea Bites 

Although fleas don’t generally live on humans due to our lack of fur, fleas will also feed on our blood. If you find yourself with bites around your ankles or end up with bites on your face after a night’s sleep, it could be a sign that fleas are taking over your residence. 

How to Prevent Fleas 

The best way to deal with a flea infestation is to avoid one in the first place. You can do this by: 

Protecting Your Pet from Fleas 

There are various ways to protect your pet from fleas, including flea collars, topical applications and chewable tablets. You may want to consult your vet to determine the best method of protection for your four-legged friend. 

Also, remember that these preventative measures aren’t interchangeable between cats and dogs. In fact, some flea products that are safe for dogs can actually be toxic for cats. Always be sure to check the label and follow all the directions for any flea product carefully. 

Keep a Tidy House 

Fleas also feed on dust, so it’s always best to keep your home tidy. Regular vacuuming of carpets, floors, furniture and drapes can help to prevent a flea infestation. And don’t forget to wash your pet’s bed regularly too!

Treat Your Yard 

In the warmer months, fleas are especially prevalent. If your pet spends a lot of time in your yard, you may want to consider treating it with an outdoor flea spray. 

How to Deal with a Flea Infestation in Your Home 

Sometimes fleas get out of control before we spot the telltale signs that they may be taking over our house. Besides treating your pet with flea shampoo and flea prevention methods, here’s what to do: 

Wash Household Items 

In order to get rid of flea eggs and larvae, you’ll want to launder everything you can. Use hot water whenever possible, as this is the best way to destroy them. 

Examples of things you should wash are blankets, slipcovers, curtains, your own bedding and your pet’s bed. 

Vacuum, Vacuum Vaccum! 

Be sure to vacuum and mop every day until you’re sure you’ve eradicated the infestation. Because fleas can be quite hardy, you can help to kill them by putting a cut up flea collar in your vacuum bag. 

And don’t forget to throw the bag out immediately to prevent any survivors from taking up residence in other parts of your home. 

Flea Powder 

Many pet stores also sell pet-safe flea powders, which you can sprinkle around the house and leave for a period of time before vacuuming. Be sure to carefully follow the directions for best results.  

Call a Professional 

If your flea problem continues or you’re just too overwhelmed to deal with the problem yourself, you may want to consider calling a professional exterminator for a quicker solution to your problem. 

Stay Aware 

The most important thing when it comes to fleas is to always keep an eye out, especially in the warmer months. Finding a few adult fleas on your pet may only be the initial sign of an impending flea infestation. 

Because fleas reproduce quickly and their eggs are hard to spot, it’s vital to check your home for the telltale signs that we mentioned, including itchy pets, flea dirt, flea eggs and larvae. 

Of course, the best plan of attack is to avoid a flea infestation in the first place by protecting your pet with a collar or some other type of prevention and keeping a tidy home. 

If you do find yourself with a flea infestation, be sure to launder infected items, vacuum and consider using a flea powder or calling a professional if the problem has become too overwhelming. 

And remember, protecting your four-legged friend from fleas will not only make them happier but keep you happier too!

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