Flies

• Horse flies derive their name from their tendency to feed on horses.Hemera Technologies/PhotoObjects.net/Getty Images
  
  There are several different types of lawn-dwelling flies that are known to bite humans, including deer flies, horse flies and yellow flies. All three flies are most common in the summer and early spring months and are most active during the daytime. These flies often wait in shady areas of the yard until a host animal passes, such as a dog, cat or human. Bites from these flies are deep, causing blood to flow, which is then ingested by the fly. These flies can transmit diseases through their bites. Deer flies can pass on tularemia, while horse flies are known to transmit anthrax.
  
  

Chiggers

• Chiggers are related to ticks. They are extremely small, only about 1/150th of an inch in diameter. Because of their small size, they are almost entirely invisible to the human eye. They are red in color but once they are engorged, they become a yellowish hue. They are the juvenile form of mites in the Trombiculidae family. Chiggers feed on mammals, including humans, but when they grow and become mites, they are vegetarians. Chiggers insert small mouth parts into the flesh, usually in areas such as hair follicles or skin depressions. When a chigger bites a mammal, it injects its saliva into the wound. This saliva reacts with skin cells to liquefy the skin tissue on which the chigger feeds.
  
  

Fleas and Ticks

• Ticks, like fleas, feed on the blood of animals and humans.Ablestock.com/AbleStock.com/Getty Images
  
  Fleas and ticks don't just bite animals such as cats and dogs but can also bite humans, causing painful itchy bumps and possibly transmitting diseases. Fleas are known to transmit tapeworms to animals and humans, while ticks are known to transmit diseases such as Lyme disease, relapsing fever and Rocky Mountain spotted fever. There are many different species of fleas and ticks but most are small and sometimes difficult to see until you have suffered a bite.
  
  

Chinch Bugs

• There are three different species of chinch bugs. Adult chinch bugs are small black and white insects measuring about 1/4 of an inch in length. In their first two nymphal stages, they are red and have a white band on the abdomen; in the last two stages, they are orange with the beginnings of wing pads. They are known for damaging lawns, particularly St. Augustine grass. While chinch bugs are considered "vegetarian," there is the possibility that they will react by biting if they are attacked.