Anne, you need a source of moisture (try a cotton-ball soaked in water), some food (veggies, fruits, dry dog food. I usually coat whatever they eat in a high-quality cricket dust. There are commercial 'cricket bites' too, but they're expensive.), and an escape-proof house. They can chew through cardboard in a matter of minutes.
I take the cricket and hold it in front of their face with tweezers. Once they realize food is at the surface, I just let the crickets swim around and get picked off, like Jaws.
Crickets make a good treat, but I wouldn't use them as a staple. With aquatic animals, you can't dust them or anything, so their nutritional value is lower than what it would be if it were dusted.
(Message edited by Joan on June 29, 2005)