Hi Misty,
I have kept crickets in an aquarium tank. I bought them from Fluker's, usually get 250 of the 4 week old ones. I use the coco fiber with a bit of green moss and bark (all from Fluker's) and I cut apart cardboard egg cartons into individual little "huts" for them to hang out in. I have two small dishes, one for the Calcium enriched gelled water and one for the cricket feed. I also give them pieces of potato, apple, or other veg/fruit. They also like oatmeal. I have a metal mesh top on the tank. They can't get out anyway, but sometimes my cat will nap on top of the tank.
Using the individual egg carton huts makes it easy to feed my salamander. I just pick up one hut, shake out crickets in their own tank until only a few are left, then cup the hut in my hand as I move over to the salamander's tank and simply shake the crickets out. Or, after I started dusting the crickets, I'd shake them into a baggie with the calcium powder to coat them and then scoop them out with a plastic spoon into the sal's tank.
When they get old enough to start chirping (really rapid movement of their wings, not rubbing their legs together as I'd been told as a child) , they outgrow their exoskeleton (the hard outer covering). That is what you see as dead bodies. I didn't know that either, until I saw some with half of it hanging off of them. They are usually white or very light brown after it comes off.
At about that age (maybe 6-7 weeks) they will mate. The males do the chirping. Most batches of Fluker's crickets I've purchased have reproduced with no help from me (!). At first the young ones look like tiny white moving dots; I thought they were mites or some such thing at first. As they get bigger, they are identifiable as crickets. By the time the older crickets are almost gone, the tiny ones have grown big enough to feed my salamander. That lets me wait a few weeks before re-ordering.
Fluker's will tell you that the life span of crickets is only 7-8 weeks, but that hasn't been my experience. I still have about 30 left from the order I got in early March.
I have really enjoyed observing these creatures. They are fascinating.
The ones that are still alive will get to live out the remainder of their lives in peace because my salamander died recently.
Good luck with your crickets. What are you feeding them to?