Don't leave food or water in areas that are easily accessible to pests and store food in containers with tight fitting lids. Sweeping and vacuuming frequently can help reduce numbers of some pests. Other effective barriers to entry include chalk, damp coffee grounds, bone meal, charcoal dust, and cayenne pepper. Individual ants or ants in trails can be killed by spraying with soapy water. Ant hills can be killed by dousing them with boiling water.
Boric acid is also useful with fleas.
Boil orange peels to make an orange-scented water spray that can be used on pets, furniture, or carpets. In order to be effective, the chips will need to be replaced when they lose their odor. Wash bedding about once a week and comb your pet regularly with a flea comb. To help with flea problems on outside animals, keep the grass cut very short and either keep the lawn very dry or very wet. Silica gel and diatomaceous earth may also be sprinkled in roach infested areas.