The world's largest roach (which lives in South America) is six inches long with a one-foot wingspan.

Roaches By the Numbers
  6 -- Number of legs on a cockroach
18 -- Number of knees on most cockroaches (at least!)
40-- Number of minutes cockroaches can hold their breath
75 -- Percentage of time that cockroaches spend just resting (how lazy can you get?)
5,000 -- Number of species of cockroaches worldwide
280 million + -- Years ago that cockroaches are thought to have originated (during the Carboniferous era)

Some female cockroaches mate once and are pregnant for the rest of their lives (bummer).

The Legend of the Headless Cockroach--
A cockroach can live for a week without its head. The roach only dies because without a mouth, because it can't drink water without his mouth and dies of thirst.

Wanna Race?
Cockroaches can run up to three miles in an hour. (Hey, it's no marathon, but it's not bad.)

Better Check Those Cracks in the Wall
Young cockroaches need only a crack as thin as a dime (about .5mm wide) to crawl into. Adult males can squeeze into a space of 1.6mm or the thickness of a quarter. Pregnant females need the most space to hide: 4.5mm or a space as tall as two stacked nickels.

Little Hearts
A cockroach heart is nothing but a simple tube with valves. The tube can pump blood backwards and forwards in the insect. The heart can even stop moving without harming the roach.

When Cold, Roaches Snuggle
Most species of roaches live in the tropics. But roaches live all over the world, including the North and South Poles. Pest cockroaches can withstand temperatures as cold as 32 degree F (0 degree C), but will die if the temperature goes much below that. In extremely cold places, however, they survive by moving in with humans.

Cockroaches can climb walls because they are equipped with a set of little claws on their feet designed for that very purpose.

Something More About Cockroaches
From:  http://scienceray.com/biology/zoology/

1. The largest species of cockroach is the Australian burrowing cockroach which can grow up to 3.5 inches (9 cm) in length and one ounce (30 grams) in weight.
2. The smallest known species of cockroach is the North American Attaphila fungicola, about three millimeters long or a bit longer than a red ant.
3. The greatest wingspan of a cockroach is the Central and South American Megaloblatta blaberoides, which has a spread of up to 7 inches.
4. The noisiest species of cockroach is the Madagascar hissing cockroaches.
5. Cockroach allergens worsen asthma symptoms more than any other known trigger.
6. Only 20 species of the known 4,000-7,500 species are suited to thrive at home.
7. Predators of cockroach are wasps and centipedes.
8. Cockroaches appeared 295-454 million years ago and have not almost changed in appearance.
9. Cockroaches don't have lungs and its organs of smell are in the antennae.
10. A headless cockroach can survive a few weeks especially if it had eaten before it was beheaded.
11. Life span of cockroaches is 1 year.
12. Cockroaches only need to be impregnated only once to be able to lay eggs for the rest of its life and lays 8 egg cases in a life time.
13. They have higher radiation resistance than vertebrates with the lethal dose 6-15 times that for human, thus, they are said to inherit the earth.
14 They have chemical traces in their feces for other cockroaches to follow to discover source of foods and water and their hiding place.
15. Cockroaches can live for 3 months without food and 1 month without water and can survive for 45 minutes without air.