If you have fleas at home, treat both "the pet" and "the home environment" at the same time: first have a veterinarian assess flea medicine for the pet, then vacuum the places where the pet sleeps and rests every day or every other day, and wash pet bedding in hot soapy water at least once a week. Eggs, larvae and pupae in the environment can still keep emerging as adults for 2 weeks after treatment, so keep vacuuming. The Chemicals Administration, Ministry of Environment (called the Chemicals Administration below) explains that Taiwan has about 30 species of flea, of which cat fleas and oriental rat fleas are the most troublesome; cat fleas live on both cats and dogs, and also bite people when they cannot find a suitable host. The Taiwan Centers for Disease Control (Taiwan CDC) notes that cat fleas are also a possible vector of murine typhus (地方性斑疹傷寒), a Category 4 notifiable infectious disease.
Note: For flea products applied directly to a pet, choose animal drugs that are labeled "for animal use" (動物用) and carry a permit number beginning 動物藥製字 or 動物藥入字 from the Ministry of Agriculture's animal and plant health inspection agency (防檢署), or follow a veterinarian's prescription. Insecticides sprayed on carpets, furniture and other parts of the environment are environmental-use pesticides regulated by the Ministry of Environment, and must carry a Ministry of Environment permit number. This article does not list drug names or doses. The flea life cycle and treatment steps are compiled from the Chemicals Administration (published October 2019) and the University of California Integrated Pest Management Program (UC IPM); UC IPM's imperial units have been converted.
First confirm it is fleas: appearance and life cycle
The Chemicals Administration describes fleas as "small as a sesame seed," with strong hind legs that can jump about 200 times their body length, and a body flattened from side to side that darts through fur. UC IPM says adults are up to about 3 mm long (1/8 inch in the original), reddish-brown and wingless. If your pet keeps scratching, it may be cat fleas. What makes fleas hard to get rid of is that most of their lives are spent not on the pet but in the environment:
| Stage | Where | How long | What to do |
|---|
| Egg | The female lays eggs on the pet, about 20-50 a day; the eggs are smooth and fall off into the pet's bed, bedding and carpets | Hatch in about 2-5 days | Wash pet bedding and vacuum |
| Larva | At the base of carpet fibers and in crevices where the pet rests; feeds on the "blood droppings" of adult fleas; needs relative humidity of 75% or more | Spin a cocoon after about 8-15 days | Vacuuming is the most effective; fewer in sunny, high-traffic places |
| Pupa (cocoon) | The cocoon is coated with hair, skin flakes and carpet fibers as camouflage | When it is cool, can stay dormant in the cocoon for up to 12 months; warmth, and the vibration of footsteps and vacuuming, stimulate emergence | Keep vacuuming so that emerging adults are picked up |
| Adult | Adult cat fleas stay mainly on the host, feeding on blood, mating and laying eggs | Live about 30-40 days on the host | Treat the pet for fleas |
The table follows UC IPM. The Chemicals Administration says it takes about three weeks from egg to adult, while UC IPM puts the whole life cycle at about 18 days at room temperature. UC IPM also notes that fleas can be on pets all year round, but numbers often surge from spring to early summer.
Flea bite symptoms, and when to see a doctor
UC IPM explains that a flea bite is usually a small red spot in the middle with a ring of redness around it, mostly not very swollen and mildly itchy. People with sensitive skin itch more and more, and some develop flea bite allergic dermatitis, which a single bite can cause and which can itch for up to 5 days after the bite. The Chemicals Administration warns that after a bite the skin can itch intensely and develop red patches, and scars from accidental scratching may take months to fade.
Fleas are also linked to disease. According to the Taiwan Centers for Disease Control (Taiwan CDC) introduction to murine typhus (last updated March 26, 2019):
- In Taiwan the vector is the oriental rat flea or the cat flea; both live on cats, dogs and house rats, and the pathogen circulates in nature in a rat-flea-rat cycle.
- The incubation period is 1-2 weeks, usually 12 days; it does not spread from person to person.
- Symptoms: headache, chills, fatigue, fever and muscle aches; 50%-80% of patients develop a rash, appearing around day 5 of the illness and starting on the trunk. Most recover on their own, but a few cases can be severe.
The following is this article's recommendation: if fever, headache or a rash appears within 1-2 weeks after being bitten, see a doctor and tell them there are fleas or rats in the home; also see a doctor if a scratched bite becomes more red, swollen, hot and painful. The Chemicals Administration adds that tapeworm infection (絛蟲病), common in pets, is transmitted through cat fleas, and UC IPM notes that children are occasionally infected too; if your pet has fleas, ask the veterinarian whether deworming is needed as well.
Flea treatment for pets: ask the vet first, and check the animal drug permit number
The Taiwan Centers for Disease Control (Taiwan CDC) advises that if you find fleas on a cat or dog at home, you should consult a veterinarian, or apply flea medicine as the veterinarian instructs. UC IPM explains that newer pet flea products (spot-on drops applied between the shoulder blades, and oral medicines) are more effective and safer than traditional insecticidal collars, powders, shampoos and sprays, so that in most cases you no longer need insecticide sprays, shampoos or powders to control fleas; it also cautions about two things:
- Not every product suits every animal. UC IPM gives the example that products containing permethrin or amitraz absolutely must not be used on cats; the following is this article's recommendation: do not use a dog flea product on a cat, and do not split a dose by weight yourself.
- UC IPM says there is no evidence that vitamin B1, brewer's yeast, herbal collars or ultrasonic flea repellers prevent fleas.
To buy pet flea medicine in Taiwan, you can check it as follows (from the FAQ of the animal drug information site of the inspection agency): a legal animal drug must have a Chinese-language label and package insert stating the permit number 動物藥製字 or 動物藥入字 No. XXXX, the name and address of the manufacturer or importer, "for animal use" (動物用) and the dosage form, ingredient content, efficacy, directions and dose, precautions, batch number and expiry date. You can use the animal drug permit lookup of the inspection agency and search by permit number, drug name or target animal "companion animals" (伴侶動物). The agency also explains that prescription animal drugs are not ordinary merchandise, and animal hospitals and companies holding a sales license may not sell them online to the general public.
Article 5 of the animal drug control act (動物用藥品管理法; amended November 9, 2016) provides that animal drugs imported without approval are "prohibited animal drugs"; the exception is travelers who, on entering the country, bring animal drugs other than those in Article 3, subparagraph 1 (biological products) for use on their own pets, where the type, dosage form and quantity meet what the competent authority has announced. If you order flea medicine online from overseas, first confirm that it is legal.
Treating the environment: vacuum, wash pet bedding, use pesticides only when necessary
UC IPM recommends first inspecting room by room to find where the pet often sleeps and lies, because that is where the most fleas are, and concentrating treatment there:
- Wash pet bedding and floor mats in hot soapy water at least once a week.
- Vacuum every day or every other day: floors, carpets (especially under furniture), under and between fabric sofa cushions, and along baseboards and cabinet edges. Vacuuming removes eggs, larvae and adults, is very damaging to larvae in carpets, and also stimulates adults in cocoons to come out.
- In severe cases, you can spot-treat carpets and fabric sofas that cannot be washed with an environmental-use insecticide containing an insect growth regulator (IGR); this kind of product kills larvae but not pupae, so adults will still emerge for about 2 weeks afterward; keep vacuuming during that time and do not spray again.
- Seal the contents of the vacuum bag or dust canister in a bag before throwing it away (recommended in the UC IPM quick guide; its main text says research shows this is not necessarily required, and this article takes the more cautious approach).
- Clean second-hand carpets and fabric sofas thoroughly before bringing them into the home.
UC IPM points out that unless a whole-room fogger contains an IGR, its coverage and lasting effect are worse than direct spot spraying, because the product does not reach larvae at the base of carpet fibers. When buying environmental-use insecticides in Taiwan, follow the Chemicals Administration's "4 musts": it must suit the pest (the label lists fleas), it must be legal (a Ministry of Environment permit number), mind the time limit, and read the label. You can confirm the permit number in the Chemicals Administration's lookup system; for the number format see the article on cockroach pesticides. When spraying, people and pets should leave first and food utensils and fish tanks should be covered; after spraying, keep doors and windows closed for 30 minutes before ventilating (Chemicals Administration).
If you have treated it yourself and still keep getting bitten after 2-3 weeks, or you have no pet but many fleas, the following is this article's recommendation: find a licensed pest-control operator (病媒防治業); on the Chemicals Administration's pest-control operator license lookup you can filter by issuing authority, Taipei City Government (臺北市政府) or New Taipei City Government (新北市政府); New Taipei also has a list of operators on its open data platform.
Fleas but no pet? Check for rats and for the previous occupant
The Taiwan Centers for Disease Control (Taiwan CDC) explains that both rat fleas and cat fleas live on cats, dogs and house rats. It advises dusting insecticide powder at rat burrow entrances and along rat runs to kill the fleas first, then killing the rats. Rat-proofing a home follows the "three nots": do not let rats in (seal rat holes and gaps; window and door screens or bars should have openings no larger than 1 cm), do not let them eat (seal food and water, and do not keep garbage containing food overnight), and do not let them live there (reduce clutter and gaps between layers). For sealing pipe chases and air-conditioner holes, see sealing rat entry points. UC IPM also mentions that wild animals such as stray cats can bring fleas; and since pupae can stay dormant for up to 12 months in cool conditions, the following is this article's inference: in a home that was left empty for a while after a previous occupant kept pets, you may suddenly be bitten once you start walking around.
Pets themselves also need proper registration and health care; for how to register dogs and cats in Taipei and New Taipei, see how to register a pet.
FAQ
Do fleas live on people?
UC IPM explains that adult cat fleas stay mainly on their host (cats and dogs) to feed and lay eggs; the Chemicals Administration notes that cat fleas turn to biting people when they cannot find a suitable host. So if the pet is treated but the environment is not, newly emerged fleas may bite people instead.
How long and how often should I vacuum?
UC IPM recommends vacuuming the pet's resting areas, carpets, fabric sofas and baseboard gaps every day or every other day. After using an environmental-use product that kills larvae, adults will still come out of cocoons for about 2 weeks, so keep vacuuming during that time and do not spray again.
What diseases can flea bites cause?
The Taiwan Centers for Disease Control (Taiwan CDC) explains that the oriental rat flea or cat flea can transmit murine typhus, with an incubation period of 1-2 weeks, usually 12 days, and symptoms of fever, headache, chills and muscle aches; 50%-80% of patients develop a rash. If you develop these symptoms after being bitten, tell the doctor about your exposure.
Can I use pet flea drops ordered online from overseas?
Under Article 5 of the animal drug control act, animal drugs imported without approval are prohibited drugs. Legal products in Taiwan carry a 動物藥製字 or 動物藥入字 permit number on the label, which you can look up in the inspection agency's animal drug permit lookup; prescription drugs may not be sold online, so ask a veterinarian.
How long does it take to clear fleas from the home?
The Chemicals Administration says fleas take about three weeks from egg to adult; UC IPM notes that pupae can stay dormant for up to 12 months, and that adults will still appear for about 2 weeks after treatment. Treating the pet and continuing to vacuum usually needs to be tracked over a period of several weeks.
Last updated: 2026-11-03
This article was compiled by SOSfix editors from public information and is for general reference only. For your own case, contact a practicing veterinarian, your city or county environmental protection department or animal protection agency; if you feel unwell, see a medical facility.
Sources
- Chemicals Administration, Ministry of Environment, environmental pesticide safe-use awareness site (環境用藥安全使用宣導網): flea ecology and control (in Chinese; published 2019-10-22, verified 2026-11-02): fleas as small as a sesame seed, jumping 200 times their body length, flattened sideways; about 2,500 species worldwide and about 30 in Taiwan, with cat fleas and oriental rat fleas the most troublesome; cat fleas bite people when they find no host, itchy bites with red patches and scars; tapeworm infection transmitted through cat fleas; larvae feed on adult fleas' blood droppings; about three weeks from egg to adult.
- University of California Statewide IPM Program: Pest Notes: Fleas (UC ANR Publication 7419, verified 2026-11-02; the page shows no update date): adults up to 1/8 inch, 20-50 eggs a day, eggs hatch in 2-5 days, larvae need 75% humidity and 8-15 days, pupae can stay dormant for 12 months, life cycle about 18 days, adults live 30-40 days on the host, bite features and allergy itching for up to 5 days, tapeworm, permethrin and amitraz not for cats, ineffective methods, vacuuming and hot soapy water washing frequency, adults still emerging 2 weeks after IGR treatment, fogger limits, wild animals bringing fleas.
- Ministry of Health and Welfare, Taiwan Centers for Disease Control (Taiwan CDC): introduction to murine typhus (in Chinese; last updated March 26, 2019, verified 2026-11-02): vectors in Taiwan are the oriental rat flea or cat flea, rat-flea-rat cycle, symptoms and rash proportion, incubation period 1-2 weeks and usually 12 days, no person-to-person spread, consult a veterinarian for pet flea treatment, dust burrows to kill fleas before killing rats, the three rat-proofing "nots" and the 1 cm screen opening.
- Ministry of Health and Welfare, Taiwan Centers for Disease Control (Taiwan CDC): murine typhus (in Chinese; verified 2026-11-02): listed as a Category 4 infectious disease, transmitted by rat flea or cat flea bites, fatality rate rises with age but is below 5% in all groups.
- Ministry of Agriculture, animal and plant health inspection agency, animal drug information site (動物用藥資訊服務網): FAQ (in Chinese; verified 2026-11-02): required label and package insert contents and permit number format (動物藥製 / 動物藥入) for legal animal drugs; prescription animal drugs may not be sold online.
- Ministry of Agriculture, animal and plant health inspection agency, animal drug information site: animal drug permit lookup (in Chinese; verified 2026-11-02): search valid or invalid permits by permit number, drug name, company, ingredient or target animal (including companion animals).
- National laws and regulations database (全國法規資料庫): animal drug control act (in Chinese; amended November 9, 2016, verified 2026-11-02): Article 3 definition of animal drugs, Article 5 unapproved imports as prohibited animal drugs and the exception for travelers' own use.
- Chemicals Administration, Ministry of Environment, environmental pesticide safe-use awareness site: how to use environmental pesticides (in Chinese; published 2019-10-21, verified 2026-11-02): which application methods suit which targets, precautions for spray insecticides (people and animals leave, cover food utensils and fish tanks, ventilate after keeping doors and windows closed for 30 minutes, do not spray at flames, people or food, children must not spray), precautions for mosquito coils and electric mosquito coils.
- Chemicals Administration, Ministry of Environment, environmental pesticide safe-use awareness site: choosing the right mosquito repellent (in Chinese; published 2019-10-24, verified 2026-11-02): the 4 musts for safe use of environmental pesticides, legal permit number formats (環部／環署衛製字、衛輸字、環衛藥防蟲字), lookup system address.
- Chemicals Administration, Ministry of Environment: pest-control operator license lookup (in Chinese; verified 2026-11-02): search by license number, issuing authority (including Taipei City Government and New Taipei City Government), person in charge or company name.
- New Taipei open data platform (資料開放平臺): list of pest-control operators in New Taipei (in Chinese; verified 2026-11-02): fields include company name, license number and address; updated yearly; agency phone (02)2953-2111 #3253.
