If you prefer to fight fleas and ticks naturally, two treatments might help. They lack the proven science of prescriptive medications but can be somewhat effective, notes Lisa Akucewich, RN, DVM, who teaches veterinary dermatology at the University of Florida in Gainesville.

Borate: This fine powder appears to interrupt the life cycle of fleas when professionally applied to carpets, upholstery and floor cracks. Poisonous to fleas, borate can remain effective up to one year, unless you have your carpets cleaned. Boric acid, however, can be toxic to infants if eaten. You can get borate from pest-control companies and via the Internet.

Nematodes: These itty-bitty yard and garden allies feast on baby and teen-age fleas nestling in the soil around your home. Like fleas, nematodes like to live in warm, moist, shady spots. They must be reapplied monthly because they can't survive temperatures below 45 degrees or above 95 degrees Fahrenheit. You can buy nematodes at nurseries and garden centers.