🩹 Biting pests

Cat flea

Ctenocephalides felis

The flea on nearly every dog as well as every cat. Jumps; bed bugs do not.

Size
About an eighth of an inch — small but clearly visible
Colour
Dark reddish-brown
Risk
Moderate
When
Peaks in warm humid months, but heated homes sustain populations year round
A cat flea in profile: a small dark reddish-brown insect flattened side to side, with spines and large hind legs.
Flattened side to side, not top to bottom, with heavy hind legs. If it jumped, it was not a bed bug. AI-generated illustration · FreePestControlInspection.com

How to identify it

Work down these in order — the first one is usually enough on its own.

  • Flattened side to side, which lets it move through fur
  • Powerful hind legs; jumps many times its own length
  • No wings
  • Flea dirt — digested blood that turns rusty red on a damp tissue

What it gets mistaken for

Most people arrive at a pest name by ruling things out. These are the ones that genuinely look similar, and the detail that separates them.

Where you will find it

  • On pets, concentrated around the neck and base of the tail
  • Pet bedding, carpet, rugs and upholstery
  • Along skirting boards and in floor cracks where larvae develop
  • Shaded outdoor areas where pets rest

Signs it is already there

You will nearly always see the evidence before you see the pest itself.

  • Pets scratching, biting at themselves or losing hair in patches
  • Flea dirt in pet bedding that goes rusty red when damp
  • Bites around ankles and lower legs on people
  • Tiny dark insects visible when parting a pet's fur

Moderate. Worth dealing with, but not an emergency.

Why it is harder to deal with than it looks

Most of a flea population is not on the pet — the eggs, larvae and pupae are in carpet, bedding and floor cracks. Pupae are resistant to treatment and can wait weeks before emerging, which is why a problem often seems to return after it looked solved.

What actually works

Treat the pet and the environment at the same time, with veterinary advice on the animal. Wash pet bedding hot, vacuum thoroughly and often — including edges and under furniture — and dispose of the vacuum contents outside. Expect to repeat as pupae hatch; a single treatment almost never finishes it.

Common questions

How do I tell a cat flea from a bed bug?

Bed bugs are larger, flattened top to bottom, and cannot jump. If it jumped, it was not a bed bug.

Where are cat flea usually found in a home?s

On pets, concentrated around the neck and base of the tail Pet bedding, carpet, rugs and upholstery Along skirting boards and in floor cracks where larvae develop.

Is a cat flea dangerous?

Bites are irritating and some pets develop flea allergy dermatitis. Fleas can transmit tapeworm to pets. Heavy infestations in young or small animals are a veterinary matter.

Identification guidance only. Under Texas law, applying pest control treatments for hire requires a licence from the Texas Department of Agriculture. This page describes what a pest looks like — it is not a diagnosis of your property or a treatment recommendation for it.