There are two main things that attract bed bugs: body heat and carbon clouds.
There are two main things that Bed Bugs are attracted to. One is our body temperature. Bed bugs can pick up on thermal images, so while we stay in one area for a long time we will heat up the environment around us. The second thing is a carbon cloud. While we are laying in one spot sleeping, we build up a carbon cloud around our bodies that will also attract bed bugs to us.