The “insects vs. humans” battle has been ongoing for as long as humans have existed, yet despite humanity's superior intellect, toolmaking ability and other advantages, the bugs keep winning because they outbreed us -- a typical human woman can, at most, have one or two offspring per year, whereas your average insect mom can produce hundreds of thousands of children in a single day.
So if you have ever wondered, “Why is it so hard to stamp out this insect infestation? I keep killing them all, yet they keep coming back,” chances are the answer is: “Actually, you didn't 'kill them all.' You killed almost all of them, but a lone pregnant female managed to survive, then spawned a brand new infestation all by herself.”
Thus, it's not surprising to read that recent genetic tests on bedbugs confirmed that prolific bedbug breeding explains much of the recent renaissance in world bedbug populations.
On Jan. 29, the BBC reported that researchers at the University of Sheffield (UK) confirmed that entire bedbug colonies of the sort that infest houses or hotels are usually descended from only a small number of bedbug females—sometimes, only one.
For awhile, it seemed bedbugs infestations were a thing of the past. In fact, if you are a Baby Boomer or member of Generation X, chances are high that throughout your childhood, you wouldn't have known bedbugs even existed if not for parents who still recited the old rhyme “Good night, sleep tight, don't let the bedbugs bite.” In mid-20th-century London, bedbugs had almost been eradicated — until their population started expanding in the 1980s.
It's believed the worldwide bedbug renaissance is due to a combination of factors. Increased human travel is likely a major factor — bedbugs are flightless, and the only way they can move large distances is if they hitch a ride with a human. Evolution also plays a role — traditional insecticides grow less effective as succeeding bug populations evolve resistance to them.
And, paradoxically, the stigma people have against bedbugs might also help them proliferate: there is a widely held, though incorrect, belief that bedbugs are attracted to filth or dirt — in other words, that bedbug infestations only affect people with poor housekeeping or hygiene standards. So people suffering through bedbug infestations might want to keep it secret, which makes solving the problem even more difficult.
What are the little critters attracted to? Well, like lots of insects, they find human blood irresistible.