Facts about cockroaches


  • Some exciting results of the research done on ‘INDOOR COCKROACH INFESTATION IN SOME URBAN AND RURAL DWELLINGS OF THAILAND’: “Cockroach surveys using sticky traps were conducted in urban areas of 14 Thailand provinces. At least 30 houses in each province were randomly sampled for cockroaches. Each house was trapped in three areas: kitchen, bedroom and outside. A total of 2,648 cockroaches was caught by 550 out of 1,542 traps (35.7%), from 337 of the 514 houses (65.6%). Overall, relative density ranged from 2.6 to 9.1 with an average of 5.2 cockroaches/house. On the average, 47.7% of the cockroaches were caught in the kitchen, 24.4% and 27.9% were caught in the bedroom and outside of dwellings, respectively.”

Chiang Mai leads the way again!
Chiang Mai, with 6 species, had the highest number of cockroach species recorded.
Journal of Vector Ecology 26 (2): 2001.

  • Cockroaches have been present on the earth for more than 400 million years.
  • Approximately 4000-7500 species of cockroaches exist.
  • “The Madagascar hissing cockroach is a large, wingless cockroach from Madagascar. The aggressive encounters between males are quite impressive. Males ram into each other with their horns and/or they push each other with their abdomens. Larger males usually win. Hissing plays an important role during male-male inter- actions. Winners of encounters hiss more than losers. The hisses of males also contain information about the size of the male hissing and may be used to assess the opponent’s size. Males can also discriminate among the hisses of familiar males and strangers”.
  • “While many insects use sound, the Madagascar hissing cockroach has a unique way of producing its hisses. In this insect, sound is produced by forcibly expelling air through a pair of modified abdominal spiracles. Spiracles are breathing pores which are part of the respiratory system of insects. Because the spiracles are involved in respiration, this method of sound production is more typical of the respiratory sound made by the vertebrates. In contrast, most other insects produce sound by rubbing body parts (e.g. crickets) or vibrating a membrane (e.g. cicadas)”.

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  • The Madagascar cockroach can reach the ripe old age of seven and produces less than 20 eggs during that long life span.
  • Cockroaches could survive a nuclear war. For humans, a dose of 800 or more rems would be lethal. The lethal dose for the American cockroach is 67,500 rems and for the German cockroach it is between 90,000 and 105,000 rems
  • A cockroach could live a long time, perhaps a month, without its head.
  • The world’s largest roach (which lives in South America) is six inches long with a one-foot wingspan.
  • Number of legs on a cockroach: 6
  • Number of knees on most cockroaches: 18 at least
  • Number of minutes cockroaches can hold their breath: 40
  • Time that cockroaches spend just resting: 75%
  • Cockroaches can run up to three miles in an hour.
  • Male cockroaches transfer sperm to females in a “gift-wrapped” package called a spermatophore. Some males cover the package in a protein-rich wrapping that the female can eat to obtain nutrients to raise her young.
  • The New Zealand Y2K Readiness Commission gave out a recipe for cockroaches in case the world ended on New Year’s Eve, 1999. “Simmer cockroaches in vinegar. Then boil with butter, farina flour, pepper and salt to make a paste. Spread on buttered bread.”
  • Cockroaches can make up to 25 body turns in a second – the highest known rate in the animal kingdom.
  • Cockroaches can respond remarkably quickly – after around 29 milliseconds – to the sensory cues that their antennae deliver.
  • Blinded and deafened cockroaches were able to navigate completely normally, even if their average speeds were lower than their sighted and air-current-sensitive counterparts.
  • Female cockroaches prefer males at the bottom of the social pecking order, and dominant males try and stop them from having their way. But when females do get the low-ranking man of their dreams, they produce fewer sons, apparently in an effort to avoid passing on his wimpishness.
  • Scientists claim some female cockroaches prefer weaker partners because they like gentle sex. A University of Manchester team has concluded stronger male cockroaches are too aggressive and often injure their partners.
  • “Why is it almost impossible to squish a cockroach before it shoots out of sight behind the refrigerator while it is often quite easy to zap it with the nozzle of a vacuum cleaner? The answer, Dr Hananel Davidowitz of the NEC Research Institute in Princeton, N.J., says, is that the jet-propelled bug thinks with its behind. The cockroach, he says, is able to sense minute changes in the air flowing round its body using tiny hairs on two posterior appendages called “cerci”—and that includes your foot coming down. Signals from those hairs feed into a group of 14 vital nerve cells which process the information. However, if a vacuum cleaner approaches from behind a cockroach, the wind goes from its head to the nozzle. It thinks the attack is from the front and it turns round and runs straight into the nozzle”.
  • Most species give birth to live young — highly unusual for insects — but a sure way to prevent other critters from feeding on their eggs.
  • If food is scarce, adolescent cockroaches can live on a very reliable resource — their parents’ feces.
  • A team in Japan has been able to stimulate the muscles in a cockroach leg with electrical signals so that its movements can be controlled. They are now investigating whether they could be used to place surveillance devices in military installations.