They can be tough to keep alive. The keys I've found are to give them plenty of space and keep their enclosure clean. For 1,000 of them, a 20g tank with a mesh top (or similarly sized plastic bin) work well. I use cardboard tubes for housing so they have plenty of surface area to hide in. Keep the food (Fresh veges) fresh and clean out dead ones and poop regularly (at least a couple few times a week). I've also found that they prefer warmer temps (70s/80s) although they get a bit noisier in warmer temps. I eventually moved to roaches though, because I found the crickets to be fragile, stinky, and not worth the hassle.