Plant a garlic clove beside the plant you want to protect. Pests of all kinds will stay away. Do not plant garlic near peas.
Basil near tomatoes will repel worms and flies.
Plant onions near carrots and beets. Onions and garlic will protect your lettuce and beans from Japanese beetles, carrot flies and aphids.
Pour boiling water on ant hills to kill ants quickly.
To protect cabbage, cauliflower, broccoli, and Brussels sprouts from the cabbage moth, use mint, sage, dill, and thyme. Do not plant cabbage near strawberries.
To deter ants, use equal parts of vinegar and water to wash your countertops, floors, cabinets, etc.
Try leaving an open bottle of pennyroyal or citronella oil in your room if mosquitoes are a problem indoors. You can also rub a little apple-cider vinegar on your skin to serve as a repellant.
Aphids and spiders will stay away from plants that have been sprayed with dishwashing liquid mixed with water. Aphids will also stay away from anise and coriander.
Use a bit of cinnamon in your cupboards and drawers to get rid of silverfish.
To kill cockroaches, mix half a cup of flour, a quarter cup of sugar, and one cup of borax together. Sprinkle along the cracks and crevices where they hide.
To catch flys make your own flypaper with honey and yellow paper.
In general leave spiders alone - they are good bugs.
To make a flea powder for dogs and cats that is organic, use Pennyroyal herb or oil and mix with cornstarch and douse the critters with some... or plant it where they can roll in it.
To get rid of lice try using petroleum jelly (Vaseline). Try it, it works great. You saturate head with it, put a plastic cap on overnight and the next day they all wash right out, no need for fine tooth comb. May require several washings though....