Scorpions may be native to desert climates, but they are nocturnal and like to find shelter in dark, cool places during the day. Your home has many ideal spots to conceal themselves in. Beyond that, they can get all the food they need from the other insects or spiders hiding in the walls of your home, and your air conditioning vents likely have condensation to provide them with cool water to drink.

In addition to a dislike of strong smells, such as peppermint, citrus, cinnamon, lavender, and eucalyptus, there are some who believe spiders dislike music or other loud sounds. You can try cranking up your music, and the spiders supposedly don’t care for the vibration, which can help keep them out of your home. Continuous vibrations can throw off their senses and make them look for a food source elsewhere.

Like many pests, fleas hide in dark, sheltered areas, including in the bed. They will seek out crevices in a mattress, so they have easy access to their hosts (you and your pets) as well as somewhere that is warm and hidden. You may also find fleas hiding in carpeting and other furniture.

Always begin by removing the gnat's source of food. Toss rotting fruit, place new fruit in the fridge, and switch the soil of your houseplants. 

The best way to get rid of gnats in the kitchen is by baiting and trapping them with something sweet. Combine water with a few drops of dish soap, apple cider vinegar, and 1 tablespoon of sugar into a bowl. Cover with plastic wrap and poke small holes to trap the gnat in the liquid.