Hi guys,
For the nigerians, keep them at 60% humidity, you can get a hydrometer at your pet store for a few bucks and about 75 to 85 degrees. This species is very hardy and super aggressive. As they get bigger they will literaly attack crickets their same size. With all nymphs they can just keel over sometimes, but I've found this species to be very hardy. You can use the 32oz deli cups to house them. I have some cool enclosures that will be available soon that are more decrative yet functional and inexpensive. Put some kind of substrate in the bottom of your container and spray it with water to mantain humidity. Also see my site for basic mantis care and several breed information.
Deadlymantis.com
Cheers,
Reggie