If there’s one good thing you can say about the record-setting drought in 2011, it’s that we didn’t have a flea problem.

How times change. After a warm, wet winter, the fleas are back in force, making wildlife, pets and their people miserable. Fleas also spread diseases and parasites, such as typhus, bubonic plague and tapeworms.

Fleas thrive in humidity above 50 percent and temperatures below 95 percent. Sounds like right now, doesn’t it? And fleas beget other fleas — fast. An adult can live for a year, survive a few months without a meal, and can lay thousands of eggs. Immature fleas can develop into adults within two weeks or can wait up to eight months, until the conditions are just right. Unfortunately, the conditions indoors usually make the grade.

Fleas are developing a resistance to some insecticides and to topical treatments such as Frontline, previously among the most effective controls. They also have a complex life cycle — from egg to larva to pupa to adult — and killing adults will not keep new ones from developing.

Controlling fleas requires treating your home, your yard and your pet simultaneously. A combination of short- and long-term solutions takes frequent cleaning and maintenance, but will get you and your pets through the warm-weather flea season healthy and relatively itch-free. 

Indoors

A graduate student in entomology once told me that wearing long white socks not only protects you from bites, but also traps fleas in the fabric when they leap up looking for a meal. The dark fleas are conspicuous in the white fabric, so it’s a good way to count them and find out whether you have a flea problem indoors or out.

Then again, Fido has probably already let you know. Flea bites are extremely irritating, and both people and pets can develop hypersensitivities and allergies to fleas.

The first step is to remove as many adult and immature fleas as possible. Give your pet a bath, and follow up by cleaning house. Vacuum your floors, then dispose of the vacuum cleaner bag. Wash pet bedding regularly in hot water.

The next step is to kill adult fleas. Choose pest control products that are toxic to fleas, but not to your pets, your children or you. Be careful even with plant-based insecticides such as pyrethrum/pyrethrins (and their synthetic imitators, pyrethroids, such as permethrin) and the citrus extracts limonene and linalool. Botanical insecticides are natural, can effectively kill fleas and are relatively safe, but can cause a reaction in sensitive animals, especially cats.

For long-term control, you have to keep immature fleas from turning into biting, egg-laying adults. For that, use insect growth regulators (IGRs), substances that interfere with insects’ ability to develop from one life stage to the next. They are low in toxicity because they aren’t insecticides. They don’t even kill fleas, so you’ll need to use them in combination with other products. Examples are sprays containing methoprene (brand name Precor) and pyriproxyfen (Nylar). Methoprene breaks down in sunlight and can only be used indoors.  IGRs are extremely effective and work for several months.

Whenever you treat your home, play it safe and temporarily remove your pets and kids. Open the windows and air out the house before letting them return.

A nontoxic option is flea traps, sticky traps that attract fleas at night with a small light.

Outdoors

Now would be a good time to treat your yard with beneficial nematodes. These microscopic worms feast on insects that spend part of their life cycle in the soil, including fleas, June bugs and roaches. Apply with a watering can or hose-end sprayer when the ground is moist, such as after a rain, and water in briefly. You can find beneficial nematodes at plant nurseries specializing in organic products, such as the Great Outdoors and the Natural Gardener. They’re sold alive but dormant, usually suspended in vermiculite or a sponge, and must be kept refrigerated before use. Bring an insulated lunch bag and an ice pack for the trip home, and use within a couple of weeks.

Sprinkling your yard with diatomaceous earth will also help control fleas and other insects. This white powder is made from ground-up rock containing the fossils of diatoms. It is a fine abrasive that scratches the exoskeletons of insects, drying them out and killing them. Protect your lungs when applying this stuff.

The IGR pyriproxyfen can also be used outdoors. It’s sold under the names Archer and Nylar, and can be applied to areas outdoors where pets spend a lot of time, such as shady spots under shrubs and decks.

Pets

Remove fleas and flea dirt (digested blood that looks like black pepper in the pet’s fur or bedding) with baths and periodic combing with a fine-toothed flea comb. If you find a flea, drop it into soapy water to kill it.

Traditional treatments such as brewer’s yeast, garlic and cedar chips are not very effective, if at all. Instead, give your pet baths and use spot-on treaments, pills or sprays during flea season.

Remember that cats are more sensitive to chemicals than dogs, but cats are also the primary hosts for fleas. In fact, the fleas you’re seeing are almost always cat fleas (Ctenocephalides felis).

If you let your cats outdoors, you owe it not just to your pet but also to your neighbors to use a flea treatment, because otherwise Fluffy is carrying fleas from yard to yard as she wanders, sabotaging the control efforts of the nice people next door. To a lesser degree, wildlife and rodents, including squirrels, also introduce fleas. Fleas from rodents are less common, but more likely to carry diseases. Cat fleas commonly harbor tapeworms (learn what to watch for here).

You can protect your pets to some degree with topical treatments such as Frontline Plus, Advantage and Revolution, which can last for one to three months. Some repel insects, others kill them on contact, and there are formulas available over the counter and by prescription. Drs. Foster and Smith, a mail-order service owned by veterinarians, has a comparison chart of the flea products it sells.

Pills include Program, Sentinel, Capstar and Comfortis. The active ingredient in Comfortis, spinosad, is also available in the pill Trifexis, which for a few dollars more also prevents heartworms. (Heartworms are spread by mosquitoes, and dogs and cats in Central Texas should take monthly heartworm preventives year-round.)

Flea-preventive pills require a prescription from a veterinarian. They work best in combination with other treatments, because your pet will constantly come into contact with new fleas introduced by outdoor cats or wildlife.

Consult your veterinarian about the safest, most effective treatments. You can also learn more from Texas AgriLife Extension’s information sheets on flea control  and safe options. California’s Integrated Pest Management Program also has good management tips.