This will prevent flies, mosquitos, and other pests from infiltrating your home during the summer months.
Ants are especially adept at seeping in through the cracks, so make sure you don't have any!
Cockroaches and other vermin are attracted to damp, dark places and are often found in these locations.
Flies are repelled by citrus fruits, pine boughs and basil. Cockroaches loathe cedar and catnip. Have some of these on hand to keep critters at bay. Cats and dogs are also great (and free) pest control.