Flea Infestations: A Complete Guide

  • Written By Dan Edwards on December 14, 2018
    Last Updated: December 17, 2020

Having to deal with a flea infestation in your home is one of the major downsides to having a dog or a cat as a pet. There are a number of ways that flea infestations can occur and develop. Unfortunately, it is possible to end up with one even if you don’t own a pet!

As a responsible homeowner, it’s important to know what signs to look out for to indicate that there is a flea infestation in your home or on your pet. As well as knowing the best methods for dealing with the issue and hopefully being able to prevent it from happening in your home in the future.

How Do Fleas Get Into the Home?

There are many places in which fleas can come from. The most common way that fleas are able to get into the home is by being transported inside while living on a pet, usually a cat or dog. For this to happen your pet will need to come into contact with a source of fleas outside the house. This can happen in a number of ways.

It is important to remember that although fleas cannot fly, their strong hind legs allow them to jump large distances both vertically and horizontally. On average, they can travel around eight inches in a horizontal direction, and just over five inches in a vertical direction. The best contenders for the flea Olympics can manage up to 19 inches horizontally, and eight inches vertically!

The legs of a flea have perfectly evolved for jumping large distances in relation to its body size

This gives these delightful insects many opportunities to land on your furry friends and hitch a free ride into their new home – your house. This often happens when your cat or dog is in contact with other people’s pets, for example when they are at an appointment with the veterinarian, on a trip to the pet groomer’s, with a dog walker or even just playing at your local dog park.

There is also the possibility that your beloved pet may pick up fleas from a wild animal that might be enjoying their time in your yard. Remember that any food source or supply of water can encourage anything from rodents to birds to raccoons, all of which are capable of carrying fleas and passing them on to other animals, including pets.

Further to this, it’s possible for a flea infestation to occur through human contact with your pet. While this is an unlikely occurrence, it is possible for humans to pick up fleas from another animal, especially if the person in question has poor personal hygiene habits!

The final way that your pet may develop a flea infestation from a source outside your home is by spending time in the wilderness. In this environment, it may inadvertently come into contact with wild animals which are carrying fleas and ticks.

How Can You Have a Flea Infestation Without Pets in the Home?

Although it’s far more common for a flea infestation in the home to be caused by a pet bringing fleas inside, there are a few ways in which you can have a flea infestation in your home without having any animals living there.

The first potential cause of a flea infestation is that the previous tenant or owner of the property you are living in may have had a pet inside the house. This, of course, means that this animal may have carried fleas and left them living in carpets and furnishings or areas of the house if this infestation was not treated correctly.

Flea Eggs On Carpet
Flea eggs in the carpet – CC Image courtesy of Denni Schnapp

The second cause of a pet free flea infestation is pests and wild animals like mice, rats, raccoons, squirrels, bats along with feral dogs and cats. These animals may either spend time in or near your property, and some may even begin to nest inside any accessible open spaces.

There are numerous different kinds of species of flea, and most of the major types have a preferred host animal. This can be a cat, dog, human, bird, rodent or even a horse. As a result, this means there are many potential visitors that you could have in your house, especially if there is a variety of wild animals living in close proximity to your home.

The final reason as to why you may have a mysterious flea infestation in your home is simply that the dogs and cats in your neighborhood may have decided that your home or porch is a very nice one to spend time in! Considering most species of flea can jump distances of between 8 and 19 inches, these little critters can find their way from the local pup to your soft furnishings a little more easily than you may like!

What Are the Signs You May Have a Flea Infestation?

If you are concerned that you may have a flea infestation in your house or on your pet, there are a number of tell-tale signs that you can look out for.

Flea Infestations on Your Pet

The most obvious sign of a flea infestation will be your pet itching and scratching themselves more often than they usually do – this is usually easier to see in dogs. This is a strong indicator that fleas are present and may already be biting your pet, causing them to scratch their irritating itchy spots.

If you examine your pet and their fur a little more closely, you may notice a number of other signs. The first would be the appearance of the fleas themselves; small brown or black looking creatures which measure about 0.08 inches long.

fleas on cat's stomach
Fleas on a cat’s stomach

You may also be able to see flea eggs or flea dirt; both of these things are very small to the naked eye and measure around 0.02 inches. Flea dirt is grainy to touch and appears on your pet as brown or black dots or flecks. On contact with water it will turn into a reddish brown liquid, so you can check whether it is flea dirt or actual dirt quite easily.

flea dirt on dog
Flea dirt on a dog’s underbelly

Although similar in size to flea dirt particles, flea eggs are much lighter in color and usually appear white or even slightly translucent. They tend to be more concentrated around the tummy area, under the tail or between the hind legs of your pet, as these are the places that fleas prefer to live on your animal.

Flea Egg
Flea Egg – CC Image courtesy of Russ Crutcher

You will probably only notice fleas, eggs, and dirt if you examine your pet, so if you are suspicious that they may be suffering from a flea infestation it’s a good idea to put on a pair of gloves and take a closer look at them. They may not like you for it, especially if your pet is a cat, but it will be for their own good and they will thank you in the long run!

Flea Infestations in the Home

While it is easiest to notice a flea infestation in your home by spotting different physical or behavioral signs with your pet, there are other ways in which you may notice that there are a large number of fleas in your home.

The first is, of course, that you may notice yourself or other family members itching and scratching flea bites on your bodies. If this happens, do not panic as firstly they may be bites from another insect like a sand fly or a mosquito. Even if they are flea bites, it may not develop into an infestation in your home if proper hygiene is followed.

If you suspect that you or someone in your home has flea bites, ensure that everyone showers thoroughly on a daily basis and washes their hair as well. You may choose to use a product that includes a tea tree scent as this oil has powerful insect repelling properties.

The other way that you will know fleas are in your home is by spotting the fleas themselves or evidence of them, such as flea dirt or flea eggs. While all of these things are very small, you may notice fleas and their dirt on white or light-colored furnishings/clothing, and pale flea eggs on darker colored surfaces.

fleas on leg
Fleas hitching a ride on a sock

How Can You Get Rid of a Flea Infestation?

Successfully dealing with a flea infestation is not a simple task. You will need to eradicate not only adult fleas, but also the young fleas, larvae and flea eggs. Only around five percent of a flea infestation in your home is represented by adult fleas; the other 95 percent is made up of larvae, pupae, and eggs.

A flea can live for anywhere between 30 to 90 days in ideal conditions, or up to over 100 days with an adequate supply of blood to feed on. An average flea lifespan is around two to three months.

Life cycle of a flea

To get rid of a flea infestation in your home, the first thing you need to do is to treat all of your pets. This can be done fairly easily and inexpensively by getting a suitable flea treatment, ideally from your veterinarian. Once applied correctly, this will take one to three days to be fully effective. If you don’t have any pets and other animals have not recently visited, the fleas could be from a previous occupant of the home.

To treat your home, you will need to collect all pet bedding and removable soft furnishings that the fleas may be living in and wash this in a machine at a temperature of at least 140 degrees Fahrenheit. This will be sufficient to kill adult fleas, larvae, pupae and flea eggs.

The final thing you need to do in order to treat your home is to use a good flea spray. These treatments are usually chemically based and are very effective at eradicating fleas from all surfaces including furniture and carpets. Many of these products include a flea growth inhibitor, which prevents young fleas from maturing into reproductively capable adults.

However, there are also many natural flea treatments available for you to try should you wish to stay away from artificial ingredients and chemicals. Heat can also be a very effective treatment if used correctly.

How Can You Prevent Flea Infestations in the Future?

There are a number of steps that you can take to help prevent flea infestations or further re-infestations in your home.

The most important step is to ensure that your pet is regularly and consistently treated with a flea prevention method. This is usually a cream which can be purchased from a vet or a store, and it needs to be applied topically to your animal’s skin and fur. This will hugely decrease the chances of your pet picking up fleas from another domestic or wild animal that it may come into contact with.

You can also reduce the chances of a flea infestation by monitoring the whereabouts of your pet and limiting the time they may spend in the wilderness or around other animals. You may also wish to check them regularly for any signs of fleas in their fur. By doing this you will be able to spot fleas on your pet and treat them before they develop into a complete infestation in your home.

Removing any temptation for a wild animal to come into your yard is a further method of preventing a flea infestation. Remember, these animals will be enticed by a potential source of food or water, so remove any standing water you may have and definitely don’t leave any food out for them, even if your children are very keen on this idea!


Although they are tiresome to contend with, dealing with a flea infestation in your home is, unfortunately, a fairly inevitable part of life. This is especially true if you are a pet owner or animal lover, even though they can occur if you do not have an animal in your home on a regular basis.

Luckily there are many ways in which you can spot a potential infestation, as well as plenty of methods for treating your home or pet for an abundance of fleas. Prevention is always the best way to treat this problem, and there are a lot of things you can do to ward off these pesky critters from invading your home in the future!