https://en.wikipedia.org/wiki/Histamine
One of the biologists on the research team who is immune to bedbug bites has been allowing the bedbugs being tested to feed on her arms, all in the name of science! After going through 35 experiments, the researchers discovered several compounds they mixed with histamine to create the most effective pheromone trap. They believe the bedbug traps will be sold commercially by next year. This trap captured 100% of bedbugs in field trials, and the chemicals in the trap only cost 10 cents! Now, if only there was such an easy way to catch mosquitoes . . .
http://www.wired.com/2014/12/building-a-better-bed-bug-trap/
http://www.msn.com/en-us/health/medical/end-could-be-in-store-for-bedbug-epidemics/ar-BBhhYad