Its been happening ever since I decided to add crickets as a staple with the roaches which was a year and a half ago. They're just silent... should I be worried? I get them from Petsmart and sometimes Petco.
Only mature males will chirp, it's their mating call. You might have immature crickets if you buy smaller ones. It's unlikely you've only gotten females, I don't know of any supplier who will sort them that way before shipping them out.
Another possibility is that you have banded crickets, which will chirp but it's quiet, almost difficult to hear the males do their thing. Banded crickets are a good choice, as far as feeders go, so if that's what you have, then it's all okay.
Sometimes they stop chirping if they're dehydrated, or too cold.