Crickets

• Crickets are omnivores, feeding on organic materials in addition to other dead insects, and often are found in a home's walls. Crickets can damage fabrics, especially when moisture is present, so care should be taken with storing textiles. Crickets are mostly a nuisance because of the sound made by males as they rub their back legs together during mating season. Nocturnal in nature, crickets are drawn to light and likely drawn to nightlights in the bathroom.
  
  

Silverfish

• The silverfish derives its name from the shiny silvery scales that line the insect's body. The insect can range in color from silver to brown or gray and does not have wings. Silverfish require high levels of humidity ranging from 75 to 90 percent. However, they are able to go long periods of time -- over a year sometimes -- without eating. Their diets consist of mostly carbohydrates but also includes paper. They can become a nuisance because their chewing damages books and wallpaper.
  
  

Cockroaches

• Cockroaches like damp, dark places.Hemera Technologies/PhotoObjects.net/Getty Images
  
  Cockroaches are one of the most widely recognized insects found in homes mainly because of its bad reputation. Recent studies have connected the cockroach to allergies, falling only behind house dust. The German cockroach is the most common roach found in homes, but the bigger American variety are attracted to damp dark places that sinks and drains provide. Baits and boric acid are the most common elimination methods and the most successful when used appropriately.
  
  

Pharaoh ant

• Pharaoh ants are drawn to toothpaste, soap and water.Thomas Northcut/Photodisc/Getty Images
  
  Several types of ants are found in homes, but Pharaoh ants are the most common. These ants are drawn to toothpaste, soap and water, which are all found in abundance in bathrooms. They nest in the damp walls and also feast on dead insects, which are quite common in house walls. They are difficult to eliminate and often require professional pest management services. Insecticide use can cause budding of colonies resulting in new colonies formed by break away ants.