1 General cockroach information

Cockroaches are insects of the order Blattaria or Blattodea, of which about 4,500 total exist with more found each year. The name cockroach comes from the Spanish word cucaracha, "chafer", "beetle", from cuca, "kind of caterpillar." The scientific name derives from the Latinized Greek name for the insect (Doric Greek: βλάττα, blátta; Ionic and Attic Greek: βλάττη, blátte'.

Of all the species of cockroach in existence only a few are ever seen in human habitation. This small number of domestic and para-domestic cockroaches are considered nuisances by most people and are generally looked upon with disgust. Of these "pest" animals the two main culprits are Blattella germanica the German cockroach, a small species that barely reaches 0.75" and Periplaneta americana the American cockroach, a medium sized roach that can exceed 1.5" in length. Both species have the ability to fly but will generally run from danger instead of fly from it.

In the pet hobby there are nearly 100 different species available, some much more rare than others. The most common are Blatta (Shelfordella) lateralis the Red Racer, a small inch long feeder cockroach that cannot climb smooth surfaces. Blaptica dubia the Guyana Orange Spotted Roach, a medium two inch or so feeder cockroach that cannot climb nor fly. Nauphoeta cinerea the Lobster Roach, a small species, barely over an inch, that can climb smooth surfaces and flutter fly. Blaberus discoidalis the Discoid Roach, a large 2-3" roach that cannot climb nor fly and is kept as a feeder and a pet. And the most famous pet cockroach Gromphadorhina portentosa the Madagascar Hissing Cockroach, a large 3-3.5" wingless roach used as both feeders or pets and is very good at climbing smooth surfaces.

Cockroaches produce young with two methods, the first is laying of an ootheca or eggcase. This ootheca will be hidden in a warm damp place normally and hatches onces the eggs are ready. The parent rarely has anything to do with the ootheca once it has been deposited and will normally produce many of them. The second method is "live" birth. I use the term sparingly because an ootheca is still involved. The live-bearing cockroaches keep the ootheca within their bodies in a brood pouch of sorts. Once the ootheca hatches the mother cockroach appears to be giving birth but is simply expelling the contents of the hatched ootheca. Some parents will sit over their brood once they have been born until their exoskeletons harden and then they are on their own. Some species have parenting behavior but this is incredibly rare with cockroaches.

One thing I always hear is "I saw an albino cockroach!", I'm here to tell you, no, you didn't. Invertebrates come in all sorts of color morphs but cannot be what is considered an albino because they lack melanin. There are light morphs which means their exoskeletons coloration is lighter than normal, however they are not albino. The main misconception comes from the method of growth. All invertebrates have an exoskeleton, to grow a cockroach must molt/shed this exoskeleton and expand a soft and very bright white new exoskeleton. This method of growth is known as Incomplete Metamorphosis (A gradual change in form through the stages of growth. There are three stages in incomplete, or simple, metamorphosis - egg, nymph, and adult. Wings develop as the nymph molts, and are functional when the insect reaches the adult stage) and is the main cause of the albino myth.

The worlds smallest cockroach yet known is the "micro heli" that lives exclusively in the nests of leaf cutter ants.

The worlds largest cockroach is always up for contention. In the pet hobby we have THE heaviest cockroach and one of the longest, but not THE longest. The bulkiest/heaviest cockroach is the Macropanesthia rhinoceros, the Australian Giant Burrowing Cockroach. It can exceed 1 oz in weight and grow longer than 3 inches.

The longest cockroach in the pet hobby is Blaberus giganteus, or the Giant Cave Cockroach. This lengthy cockroach can reach nearly 3.5 inches in length and regularly has a wingspan of 5-6 inches.

The longest recorded cockroach in the world is up for debate with Megaloblatta longipennis and Megaloblatta blaberoides, both being nearly 4 inches in length with long dark wings. These insects however have been usurped by a yet-to-be named cockroach from Borneo. This newly discovered species is a hair longer than the Megaloblatta and that does not include wings. This new species is by far the longest cockroach on record and it's all bulk, not just long wings.
Megaloblatta species:

The newly discovered wasp-like cockroach of Borneo:

There are many more considered pest roaches and pet roaches. For more information sehttp://en.wikipedia.org/wiki/Cockroach or http://www.arachnoboards.com/ab/forum.php or http://www.roachforum.com/ to learn from experienced cockroach caretakers. 

And finally, cockroaches, like all invertebrates, do not feel pain. Don't feel bad feeding them off, they don't know it hurts and some will even continue acting normally after being half consumed.