Where are all these damn cockroaches coming from?

Dear Cecil: The other day some friends and I were discussing cockroaches and we discovered all three of our apartments had been infested with the vermin at approximately the same time--i.e., September-October. Do you have any explanation for this remarkable coincidence? Don’t say they were coming in for the winter; we all lived in the same apartments last winter and had nary a roach. Curious Citizen, Baltimore

Cecil replies:

Before we continue with this discussion of “vermin,” I feel obliged to remind you, in fairness to the little buggers, that cockroaches are among the most primitive insects known to science — they beat you to the planet a good 300,000,000 years ago. Thus we might reasonably inquire who is infesting whom.

In addition, various peoples of the world have found the cockroach to be quite useful — a mash of dead cockroach and sugar has been used to cure ulcers of the skin; a tonic containing cockroach ashes has been drunk to eliminate worms; cockroaches fried in oil and garlic have been eaten to aid digestion. Today, many cockroaches grow up to become public relations executives.

Cockroaches don’t normally enter a building of their own volition; they have to be brought in. The best explanation for your problem is that one of you carried a mama roach — or possibly just some eggs (the eggs aren’t susceptible to pesticides) — into your building with the groceries or something. Judging from the autumnal appearance of the hordes, I’d mark the arrival of the contraband roach around early summer (the eggs take 30-60 days to hatch). Although roaches have no real “season” all their own, summer is their most active time.

Cecil Adams

Send questions to Cecil via cecil@straightdope.com.