Fleas in South Texas Homes: Life Cycle, Bites and Control
Most flea problems in Texas homes are cat fleas, and they live on dogs as well as cats. The adults you see are only a small part of the problem; eggs, larvae and cocoons are hidden in carpet, pet bedding and shady spots outside. Getting rid of them means treating the pets, the house and the yard at the same time, then following up while the last cocoons hatch.
To get a flea plan started, call or text (210) 281-1064 or book online.
What do fleas look like? #
Adult cat fleas are about 1/8 inch long, flat, brownish black and wingless. They can jump about 6 inches straight up. Besides cats, they feed on dogs and wild animals, and they'll bite people who hold or sleep with pets, though they don't normally live on people.
- Larvae are legless, dirty white and under 1/4 inch. They hide deep in carpet, cushions, pet beds and shaded soil.
- Flea dirt is the reddish-black specks you find on a pet or its bedding. Put some on a damp paper towel; if it smears reddish brown, it's dried blood from fleas.
- Dog fleas and human fleas look almost the same without a microscope, but cat fleas are what you'll usually find on Texas pets.
Why do fleas keep coming back? #
The answer is the life cycle. Fleas go from egg to larva to pupa to adult, and most of that happens off the animal.
- Within 2 days of feeding for the first time, a female begins laying, eventually averaging about 27 eggs daily. The smooth eggs drop off wherever the pet rests.
- Larvae feed on the droppings of adult fleas, which are mostly dried blood, and develop in 5 to 11 days.
- The pupa spins a cocoon coated with debris. An adult can wait inside for up to 5 months and break out within seconds when it senses a passing animal.
That cocoon resists insecticides, which is why fleas seem to return a week or two after a treatment. It also explains why an empty house can "come alive" with fleas when a family moves in. The good news is that larvae die when humidity drops below 50% or soil tops 95°F, so a sunny, open yard holds few fleas. The trouble spots are shady and moist: under decks and shrubs, in crawl spaces and where pets lie down.
What are the signs of fleas? #
- Pets scratching and chewing at their skin, sometimes with hair loss and scabs from flea allergy
- Flea dirt on the pet or its bedding
- Fleas hopping onto your legs near pet beds or favorite rugs
- Itchy bumps on your ankles and lower legs
A quick test from UC IPM: pull on white socks and walk slowly through the rooms where pets rest. Fleas show up clearly against the white.
Fleas but no pets? #
If you have no pets, look for animals using the house. Texas A&M AgriLife points to wildlife nesting in or under buildings, such as roof rats, squirrels, raccoons and bats, along with a previous owner's pets or stray animals. In those cases the fleas and the entry points both need attention. See our guides to rodents and wildlife.
What do flea bites look like? #
Flea bites are small, red and itchy, frequently in clusters of three. They usually land on the ankles and lower legs or where clothing fits snugly, like the waist. Bed bug bites, by comparison, show up on any skin left uncovered during sleep; see our bed bug guide. Allergic people can get hives or blisters anywhere from 12 hours to a day after a bite, and the reaction can last a week or more.
For bite care, try not to scratch, use 1% hydrocortisone cream or an antihistamine, or hold a wrapped ice pack on the spot for 10 minutes or longer. Call a health care provider if a bite looks infected or you develop a fever, headache or body aches.
Can fleas make people or pets sick? #
Mostly fleas are an itch problem, but there are real health concerns in our part of Texas:
- Flea-borne typhus. The Texas Department of State Health Services says Texas reports more cases than any other state and lists Bexar County among the newer areas where the disease has become established. Rats and their fleas carry it, and opossums and pet cats may also be involved. Symptoms include fever, headache, body aches and rash, and the CDC says antibiotics are most effective when started early. Comal County's 2025 reportable-conditions tables also list typhus.
- Plague. DSHS calls human plague rare; it moves mostly through fleas of rodents and rabbits. AgriLife notes cat fleas don't carry it.
- Other infections. Fleas can carry the bacteria behind cat scratch disease and the dog tapeworm, which children can catch by accidentally swallowing an infected flea.
- Pets. Plenty of dogs and cats react to flea saliva with flea allergy dermatitis, and heavy infestations can cause anemia in young puppies.
DSHS adds one practical rule: when rodents are part of the picture, deal with the fleas before the rodents. Fleas leave dying rodents and look for new hosts, including people.
What does it take to clear fleas? #
Start with the pets #
Every dog and cat in the home needs flea control at the same time, using a product your veterinarian recommends for that species and weight. The EPA warns that some pet products are far more dangerous for one species than for another, so never put a dog product on a cat. Products made for carpets or yards should never go on an animal.
Then the house #
Vacuuming does more than you'd think. According to AgriLife, it removes up to 30% of larvae and 60% of eggs. The University of Kentucky adds that it raises the carpet nap so treatments reach the base. Seal the bag or empty the canister outside. Wash pet bedding and throw rugs often. Insect growth regulators stop eggs and larvae from developing and are commonly combined with an adult-killing product.
And the yard, but only where fleas breed #
Whole-yard spraying is rarely needed. AgriLife and the University of Kentucky point to the spots where pets rest and run: under decks and shrubs, along fence lines, in dog houses and in shaded dirt.
Follow up #
A few fleas will keep appearing for several weeks as cocoons hatch, so keep vacuuming. AgriLife's 2025 guide sets the follow-up treatment 10 to 14 days after the initial one, while an older AgriLife web page gives 7 to 10 days. If adult fleas are still turning up after about 4 weeks, the area needs another treatment.
What doesn't work #
- Foggers. The spray drifts up and out, not down into carpet fibers and cushions where larvae live.
- Treating only one place. A treated pet in an untreated house, or a treated yard with an untreated pet, leaves a source that restarts the cycle.
How do you keep fleas from coming back? #
- Keep all pets on a flea product your vet recommends, starting before fleas build up in spring.
- Vacuum often and launder pet bedding regularly.
- Clear brush and trash, keep firewood off the ground and keep grass mowed.
- Bring pet food in at night so it doesn't draw opossums, strays and rats.
- Seal gaps that let wildlife under the house or into the attic.
How does Pest Trappers handle fleas? #
We treat fleas in homes across San Antonio, Helotes, Bulverde, New Braunfels and Cibolo.
- Inspection. The technician looks for where fleas are breeding indoors and out, and whether wildlife or rodents are feeding them.
- Prep and options. You'll get a prep list (pets treated by your vet, floors vacuumed and cleared, bedding washed, children and pets out during treatment, fish tanks and birds protected) and an explanation of the options.
- Label rules. All products go down exactly as their labels require. The work is done under Pest Trappers LLC (TPCL #0887549), a family-owned San Antonio company.
- Follow-up. The return visit is scheduled to catch fleas emerging from cocoons.
Pricing is quoted after the inspection. Book online or call or text (210) 281-1064, and the office will confirm your time. Se habla español.