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Crawling insects

Cat flea

Ctenocephalides felis · Also called: Flea, pet flea

The cat flea is a tiny, jumping insect that feeds on the blood of cats, dogs and other animals, and will bite people too. It is the flea most often found on pets in North America, and most people notice it through a scratching pet or itchy bites on the ankles.

Close-up of a tiny dark reddish-brown cat flea with a body flattened side to side, sitting in light pet fur
Quick facts

Size About 1 to 3 mm long

Colour Dark reddish-brown to almost black

Key feature Tiny wingless body flattened side to side; jumps far when disturbed

Season Year round indoors; outdoor peak late summer to early fall

Where Pet bedding, carpets, rugs, couches and floor cracks where pets rest

How to identify it

What it looks like

Adult cat fleas are tiny, about 1 to 3 mm long, and dark reddish-brown. They have no wings. The body is flattened from side to side, like a coin standing on its edge, which helps them slip through fur. Strong back legs let them jump many times their own length, so the first sign is often a dark speck that suddenly disappears.

Check pets near the base of the tail, the belly and the neck. Comb the fur over a white paper towel. Black specks that turn reddish when dampened are flea dirt, the droppings of digested blood. Flea larvae are tiny, pale and worm-like. They live deep in carpet and pet bedding, away from light, and are rarely seen.

Often confused with

Bed bug

Bed bugs are larger, flat from top to bottom and cannot jump. They hide in beds and furniture and feed mainly on people at night, not in pet fur.

Springtail

Springtails also jump but are softer, greyish or white, and do not bite. They gather in damp spots such as drains, window wells and houseplant soil.

Dog flea

The dog flea looks almost the same and needs magnification to tell apart. In North American homes, the cat flea is far more common, even on dogs.
Know the signs

Signs to look for

Pets scratching or chewing

Frequent scratching, licking or chewing, especially near the tail, belly and back legs.

Flea dirt

Black, pepper-like specks in pet fur or bedding that turn reddish-brown on a damp white paper towel.

Bites around the ankles

Small, itchy red bumps on the ankles and lower legs, often in groups or short lines.

Jumping specks

Tiny dark insects that jump onto socks, pant legs or pet fur after you walk across a carpet.

Bites after moving in

Fleas appearing soon after moving into a home where the previous residents kept pets.
Why it matters

Risks and damage

Flea bites are small, itchy red bumps, often on the ankles and lower legs. A pet with fleas may scratch until its skin is sore or patchy, and some pets become allergic to the bites. Pets can get tapeworm by swallowing a flea while grooming. Very young or small animals with many fleas can lose enough blood to become weak. Serious illness in people from household fleas is rare.

In Alberta

Alberta’s cold winters and dry air keep flea numbers lower than in humid regions, but fleas still turn up in Edmonton, Calgary and across the province. Pets often bring them home after travel or contact with wildlife. Indoors, fleas can keep breeding in carpets and pet bedding.

Did you know?

Health Canada notes that fleas can jump up to about 20 cm straight up and 41 cm forward. That is many times their own body length, which is how they move so easily between the floor and a passing pet.

Prevention

How to keep them out

Vacuum often

Vacuum carpets, rugs, furniture and pet resting spots every day or two during a problem. Empty the canister or bag outside.

Wash pet bedding hot

Wash pet bedding, throws and washable rugs in hot water and dry them on high heat. Repeat every week or two.

Check pets with a flea comb

Comb pets over a white towel, especially after trips, boarding or visits to off-leash parks and daycares.

Limit contact with other animals

Keep cats indoors, and keep dogs away from stray animals, wildlife dens and burrows, where fleas are often picked up.

Keep wildlife away

Once you are sure no animal is inside, close gaps under decks, porches and sheds so skunks and stray cats cannot den near the house.
When to call

When it is time to bring in a professional

Call a professional if fleas keep coming back after pets are treated, if people in the home are being bitten, or if you find fleas in a home with no pets. Eggs and cocoons in carpets and floor cracks keep adding fleas for weeks. Technica’s licensed technicians can treat the home while your vet cares for your pets.

Common questions

Frequently asked questions

Can cat fleas live on people?

Cat fleas bite people but do not live on us. They need a furry host such as a cat or dog to breed. When pets are away or gone, hungry fleas will bite people instead, which is why bites often show up after a pet leaves or when moving into a new home.

Why do fleas appear in a home that has been empty?

Flea pupae can wait inside their cocoons for weeks or months. Vibration, warmth and the carbon dioxide we breathe out signal the adult fleas inside to come out. That is why people are sometimes bitten soon after moving into a home where pets used to live.

Will treating my pet get rid of fleas in the house?

It helps, but much of a flea problem is in the home as eggs, larvae and cocoons, not on the pet. Pets, bedding, carpets and furniture all need attention at the same time. It can take several weeks for all the adults in cocoons to come out and be cleared.

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