I am sure that some of you have seen something like this:
This creature's existence dated as far back as more than 280 million years. This female here was laying or carrying her egg case and believe it or not, this was my first time seeing such.
An interesting fact about these female cockroaches is that they only mate and pregnant once for the rest of their entire life cycle. Cockroaches usually live up to a year and varies depending on the species.
The egg sac or ootheca holds about 30 to 40 long, thin eggs all packed like frankfurters in a case. The egg hatches using combined pressure of the hatchlings gulping air and these initially bright white nymphs continue inflating themselves with air, becoming harder and darker within four hours.
Depending on the species of a female cockroach, she will retain the ootheca until it hatches , for example the German Cockroach (Blattella germanica). While other species, for eg. the American Cockroach (Periplaneta americana) female will not retain the ootheca for more than one day after formation and she will find a suitable hiding spot to drop and glue the ootheca until it hatches in 50-55 days. In my opinion, this American Cockroach is the ugliest cockroach that you can find commonly everywhere here.
This picture of female cockroach is a much prettier one as compared to the common American Cockroaches. She was spotted in the late morning and remained motionless on the the same spot for a few hours. As I looked closer only to realise her ootheca that she was carrying. Assistance needed to help id the exact species of this pretty cockroach...
All that you need to know about cockroaches can be found in Joe Kunkel's Cockroach FAQ.
Other interesting links on roaches: