I just bought some adult crickets from Petco and was surprised at how quiet they are... literally, no noise and it's been hours. I briefly read something about how it can be a sign they have a parasite. Apparently the parasite can control the crickets somehow. Has anyone had an experience with this? I'm considering returning them, but I don't want them to put them back on the shelf if they actually have parasites. I haven't fed any to my bearded dragon because I'm just not sure why they aren't chirping.