All over the Internet it says bed bugs are attracted to Carbon Dioxide. This is why they congregate around beds. Your bed is the only place you are stationary for long enough periods of the day to exhale enough Carbon Dioxide. So, I grant that there seems to be a consensus that they are in fact attracted to Carbon Dioxide. But, why? Certainly they're not breathing it. (Are they?) I was under the assumption that all animals are aerobic.
It's nothing to do with what they breath, they're attracted to carbon dioxide because it's generally a good indication of the presence of a larger organism (such as a person) so they're simply following the "scent" (for want of a better euphemism) to their food (in this case you, or whoever happens to be in the bed), the traps in your links just take advantage of this to trap and kill them.