Living With Bites
The insects most likely to bite humans in Indiana are mosquitoes, flies, fleas and more recently bedbugs. Most blood feeding insects that pierce the skin have salivary secretions that are injected into the bite area. These secretions typically contain anti-coagulants, proteins and other factors that prevent the blood from clotting and blocking the feeding tube or digestive system of the insect. When the insect finishes feeding, it leaves behind proteins and other feeding secretions that can…
Source: Living With Insects Blog