A discarded sofa by sidewalk.
Humans spread them. Inadvertently, of course. They feed on our blood. They nest in our beds. We place objects on or near our beds and couches. Then we move those objects with Bed Bugs snuck in them. And, bingo!
We feed the population and we migrate them from place to place. So what caused Bed Bugs’ spread? Humans!
Bed Bugs primarily nest in beds and couches. In cases of severe infestations, they are found to be on the person of people in transit facilities, medical offices and other places of social and business activity. Also, they are found to be in books, clothing and other items that are common to be found in bed rooms. When these items are transported, many a times, so are the bed bugs.