Against pests in the home, the best offense is a good defense. The first step is to make the house — especially the kitchen — unattractive to insects by cleaning up food spills immediately, keeping hard-to-reach areas reasonably clean, and removing clutter that can hide pests.

It’s best to store foods that are attractive to pests, such as flour, in the refrigerator. Water attracts pests, so leaky faucets and pipes should be promptly repaired. Doors and windows should be well screened. Cloths should be regularly cleaned and aired, and properly stored in paper or cardboard boxes that are sealed against moths.

A number of nontoxic substances can be used to repel insects. Generally, they are highly fragrant or volatile herbs or spices. Powdered red chill pepper, peppermint, bay leaves, cloves, citrus oil, lavender, rosemary, tobacco, peppercorns, and cedar oil can repel various types of insects.

Insects can be trapped and killed without resorting to dangerous chemicals.

Generally a poison nontoxic to humans is mixed with a food that insects find attractive, and spread in the infested area. Examples are oatmeal (attractive) and plaster-of-Paris (poisonous), and cocoa powder and flour (attractive) and borax (poisonous). Old-fashioned flypaper — not a hanging strip of insecticide — is an effective trap.

For specific house pests, try these natural home remedy pestcides:

For ants: Sprinkle powdered red chill pepper, paprika, dried peppermint, or borax where the ants are entering.

For beetles: Kill manually when you see them.

For cockroaches: Mix by stirring and sifting 1 ounce TSP, 6 ounces borax, 4 ounces sugar, and 8 ounces flour. Spread on floor of infested area. Repeat after 4 days and again after 2 weeks.

For fleas: Feed pet brewer’s yeast in powder mixed with food or by tablets.

For moths: Air clothes well in the sun; store in airtight containers, and scatter sachets of lavender, cedar chips, or dried tobacco in with clothing.

For rats and mice: Again, prevention may be the best cure. Holes in exterior or interior walls should be closed off and storage spaces kept orderly. Garbage should be kept tightly covered. To catch rodents, the most efficient system is the oldest: a cat. Next best are mouse and rat traps.

For termites: Any wooden parts of the house should be at least 18 inches off the ground, as subterranean termites cannot tolerate being exposed to air and light. They have to build easily visible mud tunnels to get at available wood.

However, most existing houses have only about an 8-inch clearance between wooden parts and the ground, which makes the wood vulnerable. Metal shields may help discourage termites, but they cannot prevent infestations.

To treat existing termite infestations, there are a few nontoxic alternatives: The “Extermax” system, available in California; and the use of a particular species of nematodes to eat them, a system available from N-Viro Products, Ltc.

For gardens: In hardware stores, look for new brands of safer insecticides that use soap-and water solution to get rid of aphids, or pyrethrum for a number of applications. As more and more people understand the hazards of organic chemicals in the home, market pressure will encourage the introduction of safer products.

Several naturally derived pesticides exist which, in some cases, are less toxic to humans than the organophosphates, carbamates, or organochlorines now widely used. Nicotine is the most toxic, poisonous both to humans and to other mammals, as well as to birds and fish. It is not available commercially for home gardeners because of its hazards.

Rotenone, moderately toxic to humans, kills a wide range of insects; however, it should never be used near a waterway, as it is very toxic to fish. Ryania kills only a few species, including the European corn borer, codling moth, and cranberry fruit worm.

Pyrethrum is relatively nontoxic to humans and only slightly toxic to aquatic life, so it may be the best choice for home gardens. Sabadilla controls lice, leafhoppers, squash bugs, striped cucumber beetles, and chinch bugs. It has low toxicity to wildlife, but it may be toxic to bees.

For lawns: Herbicides are most often used to kill “unsightly” weeds in gardens and yards, and are employed by lawn care companies to maintain the perfect appearance of turf around homes, lawns and golf courses. Basically, the safe alternative to herbicides is simple: pull weeds by hand. There are no really safe herbicides.